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	Author	Ejrnaes, M.; Cristiano, R.; Quaranta, O.; Pagano, S.; Gaggero, A.; Mattioli, F.; Leoni, R.; Voronov, B.; Gol’tsman, G.
	Title	A cascade switching superconducting single photon detector			Type	Journal Article
	Year	2007	Publication	Appl. Phys. Lett.	Abbreviated Journal	Appl. Phys. Lett.
	Volume	91	Issue	26	Pages	262509 (1 to 3)
	Keywords	SSPD, SNSPD, parallel-wire
	Abstract	We have realized superconducting single photon detectors with reduced inductance and increased signal pulse amplitude. The detectors are based on a parallel connection of ultrathin NbN nanowires with a common bias inductance. When properly biased, an absorbed photon induces a cascade switch of all the parallel wires generating a signal pulse amplitude of 2mV. The parallel wire configuration lowers the detector inductance and reduces the response time well below 1ns. This work was performed in the framework of the EU project “SINPHONIA” NMP4-CT-2005-016433.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1418
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	Author	Cherednichenko, S.; Drakinskiy, V.; Baubert, J.; Lecomte, B.; Dauplay, F.; Krieg, J.-M.; Delorme, Y.; Feret, A.; Hübers, H.-W.; Semenov, A. D.; Gol’tsman, G. N.
	Title	2.5 THz multipixel heterodyne receiver based on NbN HEB mixers			Type	Abstract
	Year	2007	Publication	Proc. 18^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 18^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	112
	Keywords	NbN HEB mixers
	Abstract	A 16 pixel heterodyne receiver for 2.5 THz has been developed based on NbN superconducting hot-electron bolometer (HEB) mixers. The receiver uses a quasioptical RF coupling approach where HEB mixers are integrated into double dipole antennas on 1.5μm thick Si3N4 / SiO2 membranes. Spherical mirrors (one per pixel) and backshort distance from the antenna have been used to design the output mixer beam profile. The camera design allows all 16 pixel IF readout in parallel. Measurements of the mixers sensitivity and the input RF band are presented, and compared against calculations.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1419
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	Author	Semenov, A.; Richter, H.; Smirnov, A.; Günther, B.; Hübers, H.-W.; Il’in, K.; Siegel, M.; Gol’tsman, G.; Drakinskiy, V.; Merkel, H.; Karamarkovic, J.
	Title	Development of HEB mixers for GREAT and for security screening			Type	Abstract
	Year	2007	Publication	Proc. 18^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 18^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	184
	Keywords	NbN HEB mixers, GREAT
	Abstract	We report the study on the quasioptical coupling efficiency and the gain bandwidth of NbN hot-electron bolometer mixers developed for the 4.7 THz channel of the German receiver for Astronomy at THz-frequencies (GREAT) and for security screening at subterahertz frequencies. Radiation coupling efficiency and directive properties of integrated lens antennas with log-spiral, log-periodic and double-slot planar feeds coupled to a hot-electron bolometer were experimentally studied at frequencies from 1 THz to 6 THz and compared with simulations based on the method of moments and the physical-optics ray tracing. For all studied antennas the modeled spectral dependence of the coupling efficiency fits to the experimental data obtained with both Fourier transform spectroscopy and noise temperature measurements only if the complex impedance of the bolometer is explicitly taken into account. Our experimental data did not indicate any noticeable contribution of the quantum noise to the system noise temperature. The experimentally observed deviation of the beam pattern from the model prediction increases with frequency and is most likely due to a non- ideality of the presently used lenses. Study of the intermediate frequency mixer gain at local oscillator (LO) frequencies between 2.5 THz and 0.3 THz showed an increase of the gain bandwidth at low LO frequencies that was understood as the contribution of the direct interaction of magnetic vortices with the radiation field. We have found that the non- homogeneous hot-spot model more adequately describes variation of the intermediate frequency bandwidth with the applied local oscillator power than any of uniform mixer models. The state-of-the-day performance of the GREAT 4.7-THz channel and the 0.8-THz security scanner will be presented.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1420
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	Author	Ryabchun, Sergey; Tong, Cheuk-yu Edward; Blundell, Raymond; Kimberk, Robert; Gol’tsman, Gregory
	Title	Stabilisation of a terahertz hot-electron bolometer mixer with microwave feedback control			Type	Conference Article
	Year	2007	Publication	Proc. 18^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 18^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	193-198
	Keywords	waveguide NbN HEB mixers, Allan variance, stability
	Abstract	We report on implementation of microwave feedback control loop to stabilise the performance of an HEB mixer receiver. It is shown that the receiver sensitivity increases by a factor of 4 over a 16-minute scan, and the corresponding Allan time increases up to 10 seconds, as opposed to an open loop value of 1 second. Our experiments also demonstrate that the receiver sensitivity is limited by the intermediate frequency chain.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1421
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	Author	Gol’tsman, G. N.
	Title	The “Millimetron” project, a future space telescope mission			Type	Abstract
	Year	2007	Publication	Proc. 18^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 18^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	255
	Keywords	Millimetron space observatory, VLBI
	Abstract	The goal of the Millimetron project is to develop a space observatory operating in the millimeter, sub-millimeter and infrared wavelength ranges using a 12-m actively cooled telescope in a single-dish mode and as an interferometer with the space-ground and space-space baselines (the later after the launch of the second identical space telescope). The Millimetron’s main reflector and other optics will be cooled down to 4K thus enabling astronomical observations with super high sensitivity in MM and subMM (down to nanoJansky level). Heterodyne observations in an interferometer mode at frequencies 0.1-1 THz will provide super high angular resolution. The main instruments, planned to be installed are wide-range imaging arrays, radiometers with spectrometers and polarimeters, VLBI heterodyne receivers, and Mikelson type interferometer devices. Wide-range MM and subMM imaging arrays and spectrometers will be based on a superconducting hot electron direct detectors with Andreev mirrors operating at 0.1 K. Such detectors are the best candidates to reach the noise equivalent power level of 10 -19 -10 -20 W/√Hz. Heterodyne receivers will be both SIS based superconducting integrated receiver with flux-flow oscillator as LO (0.1-0.9 THz range) and HEB based receivers using multiplied Gunn oscillator as LO for 1-2 THz range and quantum cascade lasers as LO for 2-5 THz range. For observations in middle IR region there will be installed large arrays of superconducting single photon detectors, providing imaging with very high dynamic range and ultimate sensitivity.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1422
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	Author	Bell, M.; Sergeev, A.; Mitin, V.; Bird, J.; Verevkin, A.; Gol’tsman, G.
	Title	One-dimensional resistive states in quasi-two-dimensional superconductors: Experiment and theory			Type	Journal Article
	Year	2007	Publication	Phys. Rev. B	Abbreviated Journal	Phys. Rev. B
	Volume	76	Issue	9	Pages	094521 (1 to 5)
	Keywords	uasi-two-dimensional superconductors, NbN
	Abstract	We investigate competition between one- and two-dimensional topological excitations—phase slips and vortices—in the formation of resistive states in quasi-two-dimensional superconductors in a wide temperature range below the mean-field transition temperature TC0. The widths w=100nm of our ultrathin NbN samples are substantially larger than the Ginzburg-Landau coherence length ξ=4nm, and the fluctuation resistivity above TC0 has a two-dimensional character. However, our data show that the resistivity below TC0 is produced by one-dimensional excitations—thermally activated phase slip strips (PSSs) overlapping the sample cross section. We also determine the scaling phase diagram, which shows that even in wider samples the PSS contribution dominates over vortices in a substantial region of current and/or temperature variations. Measuring the resistivity within 7 orders of magnitude, we find that the quantum phase slips can only be essential below this level.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1423
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	Author	Gao, J. R.; Hajenius, M.; Tichelaar, F. D.; Klapwijk, T. M.; Voronov, B.; Grishin, E.; Gol’tsman, G.; Zorman, C. A.; Mehregany, M.
	Title	Monocrystalline NbN nanofilms on a 3C-SiC∕Si substrate			Type	Journal Article
	Year	2007	Publication	Appl. Phys. Lett.	Abbreviated Journal	Appl. Phys. Lett.
	Volume	91	Issue	6	Pages	062504 (1 to 3)
	Keywords	NbN films, nanofilms
	Abstract	The authors have realized NbN (100) nanofilms on a 3C-SiC (100)/Si(100) substrate by dc reactive magnetron sputtering at 800°C. High-resolution transmission electron microscopy (HRTEM) is used to characterize the films, showing a monocrystalline structure and confirming epitaxial growth on the 3C-SiC layer. A film ranging in thickness from 3.4to4.1nm shows a superconducting transition temperature of 11.8K, which is the highest reported for NbN films of comparable thickness. The NbN nano-films on 3C-SiC offer a promising alternative to improve terahertz detectors. For comparison, NbN nanofilms grown directly on Si substrates are also studied by HRTEM. The authors acknowledge S. V. Svetchnikov at National Centre for HRTEM at Delft, who prepared the specimens for HRTEM inspections. This work was supported by the EU through RadioNet and INTAS.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1425
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	Author	Ryabchun, S.; Tong, C.-Y. E.; Blundell, R.; Kimberk, R.; Gol'tsman, G.
	Title	Study of the effect of microwave radiation on the operation of HEB mixers in the terahertz frequency range			Type	Journal Article
	Year	2007	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	17	Issue	2	Pages	391-394
	Keywords	NbN HEB mixers
	Abstract	We have investigated the effect of injecting microwave radiation, with a frequency much lower than that corresponding to the energy gap of the superconductor, on the performance of the hot-electron bolometer mixer incorporated into a THz heterodyne receiver. More specifically, we show that exposing the mixer to microwave radiation does not cause a significant rise of the receiver noise temperature and fall of the mixer conversion gain so long as the microwave power is a small fraction of local oscillator power. The injection of a small, but controlled amount of microwave power therefore enables active compensation of local oscillator power and coupling fluctuations which can significantly degrade the gain stability of hot electron bolometer mixer receivers.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1051-8223	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1427
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	Author	Dauler, E. A.; Robinson, B. S.; Kerman, A. J.; Yang, J. K. W.; Rosfjord, E. K. M.; Anant, V.; Voronov, B.; Gol'tsman, G.; Berggren, K. K.
	Title	Multi-element superconducting nanowire single-photon detector			Type	Journal Article
	Year	2007	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	17	Issue	2	Pages	279-284
	Keywords	SSPD, SNSPD
	Abstract	A multi-element superconducting nanowire single photon detector (MESNSPD) is presented that consists of multiple independently-biased superconducting nanowire single photon detector (SNSPD) elements that form a continuous active area. A two-element SNSPD has been fabricated and tested, showing no measurable crosstalk between the elements, sub-50-ps relative timing jitter, and four times the maximum counting rate of a single SNSPD with the same active area. The MESNSPD can have a larger active area and higher speed than a single-element SNSPD and the input optics can be designed so that the detector provides spatial, spectral or photon number resolution.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1051-8223	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1428
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	Author	Jiang, L.; Antipov, S. V.; Voronov, B. M.; Gol'tsman, G. N.; Zhang, W.; Li, N.; Lin, Z. H.; Yao, Q. J.; Miao, W.; Shi, S. C.; Svechnikov, S. I.; Vakhtomin, Y. B.
	Title	Characterization of the performance of a quasi-optical NbN superconducting HEB mixer			Type	Journal Article
	Year	2007	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	17	Issue	2	Pages	395-398
	Keywords	NbN HEB mixers, noise temperature
	Abstract	In this paper we focus mainly on the investigation of the performance of a quasi-optical (planar log-spiral antenna) phonon-cooled NbN superconducting hot electron bolometer (HEB) mixer, which is cryogenically cooled by a close-cycled 4-K cryocooler, at 500 and 850 GHz frequency bands. The mixer's noise performance, stability of IF output power, and local oscillator (LO) power requirement are characterized for three NbN superconducting HEB devices of different sizes. The transmission characteristics of Mylar and Zitex films with incidence waves of an elliptical polarization are also examined by measuring the mixer's noise temperature. The lowest receiver noise temperatures (with no corrections) of 750 and 1100 K are measured at 500 and 850 GHz, respectively. Experimental results also demonstrate that the bigger the HEB device is, the higher the stability of IF output power becomes.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1051-8223	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1429
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	Author	Zhang, Wen; Li, Ning; Jiang, Ling; Miao, Wei; Lin, Zhen-Hui; Yao, Qi-Jun; Shi, Sheng-Cai; Chen, Jian; Wu, Pei-Heng; Svechnikov, S. I.; Vachtomin, Y. B.; Antipov, S. V.; Voronov, B. M.; Gol'tsman, G. N.
	Title	Noise behaviour of a THz superconducting hot-electron bolometer mixer			Type	Journal Article
	Year	2007	Publication	Chinese Phys. Lett.	Abbreviated Journal	Chinese Phys. Lett.
	Volume	24	Issue	6	Pages	1778-1781
	Keywords	NbN HEB mixers
	Abstract	A quasi-optical superconducting NbN hot-electron bolometer (HEB) mixer is measured in the frequency range of 0.5–2.5 THz for understanding of the frequency dependence of noise temperature of THz coherent detectors. It has been found that noise temperature increasing with frequency is mainly due to the coupling loss between the quasi-optical planar antenna and the superconducting HEB bridge when taking account of non-uniform distribution of high-frequency current. With the coupling loss corrected, the superconducting HEB mixer demonstrates a noise temperature nearly independent of frequency.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0256-307X	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1430
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	Author	Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Gorska, M.; Rieger, E.; Dorenbos, P.; Zwiller, V.; Milostnaya, I.; Minaeva, O.; Antipov, A.; Okunev, O.; Korneev, A.; Smirnov, K.; Voronov, B.; Kaurova, N.; Gol’tsman, G.N.; Kitaygorsky, J.; Pan, D.; Pearlman, A.; Cross, A.; Komissarov, I.; Sobolewski, R.
	Title	Fiber-coupled NbN superconducting single-photon detectors for quantum correlation measurements			Type	Conference Article
	Year	2007	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	6583	Issue		Pages	65830J (1 to 11)
	Keywords	NbN SSPD, SNSPD, superconducting single-photon detectors, single-photon detectors, fiber-coupled optical detectors, quantum correlations, superconducting devices
	Abstract	We have fabricated fiber-coupled superconducting single-photon detectors (SSPDs), designed for quantum-correlationtype experiments. The SSPDs are nanostructured ( 100-nm wide and 4-nm thick) NbN superconducting meandering stripes, operated in the 2 to 4.2 K temperature range, and known for ultrafast and efficient detection of visible to nearinfrared photons with almost negligible dark counts. Our latest devices are pigtailed structures with coupling between the SSPD structure and a single-mode optical fiber achieved using a micromechanical photoresist ring placed directly over the meander. The above arrangement withstands repetitive thermal cycling between liquid helium and room temperature, and we can reach the coupling efficiency of up to 33%. The system quantum efficiency, measured as the ratio of the photons counted by SSPD to the total number of photons coupled into the fiber, in our early devices was found to be around 0.3 % and 1% for 1.55 &mgr;m and 0.9 &mgr;m photon wavelengths, respectively. The photon counting rate exceeded 250 MHz. The receiver with two SSPDs, each individually biased, was placed inside a transport, 60-liter liquid helium Dewar, assuring uninterrupted operation for over 2 months. Since the receiver’s optical and electrical connections are at room temperature, the set-up is suitable for any applications, where single-photon counting capability and fast count rates are desired. In our case, it was implemented for photon correlation experiments. The receiver response time, measured as a second-order photon cross-correlation function, was found to be below 400 ps, with timing jitter of less than 40 ps.
	Address
	Corporate Author				Thesis
	Publisher	Spie	Place of Publication		Editor	Dusek, M.; Hillery, M.S.; Schleich, W.P.; Prochazka, I.; Migdall, A.L.; Pauchard, A.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Photon Counting Applications, Quantum Optics, and Quantum Cryptography
	Notes				Approved	no
	Call Number				Serial	1431
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	Author	Zinoni, C.; Alloing, B.; Li, L. H.; Marsili, F.; Fiore, A.; Lunghi, L.; Gerardino, A.; Vakhtomin, Y. B.; Smirnov, K. V.; Gol’tsman, G. N.
	Title	Single-photonics at telecom wavelengths using nanowire superconducting single photon detectors			Type	Conference Article
	Year	2007	Publication	CLEO/QELS	Abbreviated Journal	CLEO/QELS
	Volume		Issue		Pages	QTuF6 (1 to 2)
	Keywords	SSPD, SNSPD
	Abstract	Novel single-photon detectors based on NbN superconducting nanostructures promise orders-of- magnitude improvement over InGaAs APDs. We demonstrate this improved performance for the first time by measuring the g(2)(τ) on single photon states produced by a quantum dot at telecom wavelength.
	Address
	Corporate Author				Thesis
	Publisher	Optical Society of America	Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies
	Notes				Approved	no
	Call Number	Zinoni:07			Serial	1432
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	Author	Kerman, A. J.; Dauler, E. A.; Yang, J. K. W.; Rosfjord, K. M.; Anant, V.; Berggren, K. K.; Gol’tsman, G. N.; Voronov, B. M.
	Title	Constriction-limited detection efficiency of superconducting nanowire single-photon detectors			Type	Journal Article
	Year	2007	Publication	Appl. Phys. Lett.	Abbreviated Journal	Appl. Phys. Lett.
	Volume	90	Issue	10	Pages	101110 (1 to 3)
	Keywords	SSPD, SNSPD
	Abstract	We investigate the source of the large variations in the observed detection efficiencies of superconducting nanowire single-photon detectors between many nominally identical devices. Through both electrical and optical measurements, we infer that these variations arise from “constrictions:” highly localized regions of the nanowires where the effective cross-sectional area for superconducting current is reduced. These constrictions limit the bias-current density to well below its critical value over the remainder of the wire, and thus prevent the detection efficiency from reaching the high values that occur in these devices when they are biased near the critical current density. This work is sponsored by the United States Air Force under Contract No. FA8721-05-C-0002.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1433
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	Author	Słysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Górska, M.; Zwiller, V.; Latta, C.; Böhi, P.; Pearlman, A.J.; Cross, A.S.; Pan, D.; Kitaygorsky, J.; Komissarov, I.; Verevkin, A.; Milostnaya, I.; Korneev, A.; Minayeva, O.; Chulkova, G.; Smirnov, K.; Voronov, B.; Gol’tsman, G.N.; Sobolewski, R.
	Title	Fibre-coupled, single photon detector based on NbN superconducting nanostructures for quantum communications			Type	Journal Article
	Year	2007	Publication	J. Modern Opt.	Abbreviated Journal	J. Modern Opt.
	Volume	54	Issue	2-3	Pages	315-326
	Keywords	NbN SSPD, SNSPD
	Abstract	We present a novel, two-channel, single photon receiver based on two fibre-coupled, NbN, superconducting, single photon detectors (SSPDs). The SSPDs are nanostructured superconducting meanders and are known for ultrafast and efficient detection of visible-to-infrared photons. Coupling between the NbN detector and optical fibre was achieved using a micromechanical photoresist ring placed directly over the SSPD, holding the fibre in place. With this arrangement, we obtained coupling efficiencies up to ∼30%. Our experimental results showed that the best receiver had a near-infrared system quantum efficiency of 0.33% at 4.2 K. The quantum efficiency increased exponentially with the photon energy increase, reaching a few percent level for visible-light photons. The photoresponse pulses of our devices were limited by the meander high kinetic inductance and had the rise and fall times of approximately 250 ps and 5 ns, respectively. The receiver's timing jitter was in the 37 to 58 ps range, approximately 2 to 3 times larger than in our older free-space-coupled SSPDs. We stipulate that this timing jitter is in part due to optical fibre properties. Besides quantum communications, the two-detector arrangement should also find applications in quantum correlation experiments.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0950-0340	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1434
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	Author	Jiang, Ling; Miao, Wei; Zhang, Wen; Li, Ning; Lin, Zhen Hui; Yao, Qi Jun; Shi, Sheng-Cai; Svechnikov, Sergey I.; Vakhtomin, Yury B.; Antipov, Sergey V.; Voronov, Boris M.; Kaurova, Natalia S.; Gol'tsman, Gregory N.
	Title	Characterization of quasi-optical NbN phonon-cooled superconducting HEB mixers			Type	Conference Article
	Year	2006	Publication	Proc. 17^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 17^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	55-58
	Keywords	NbN HEB mixers
	Abstract	In this paper, we thoroughly investigate the performance of quasi-optical NbN phonon-cooled superconducting hot-electron bolometer (HEB) mixers, cryogenically cooled by a close-cycled 4-K refrigerator at 500 GI-1z and 850 GHz. The uncorrected lowest receiver noise Abstract---In temperatures measured are 800 K at 500 CHz without anti-reflection coating, and 1000 K @ 850 GHz with a 50 11M thick Mylar anti-reflection coating. The dependence of receiver noise temperature on the critical current and bath temperature of HEB mixer is also investigated here. Lifetime of quasi-optical superconducting NbN HEB mixers of different volumes, room temperature resistances, and critical temperatures are thoroughly studied. Increased room temperature resistance with time over the initial resistance changes between 1 and 1.2, and the reduced critical current with time over the initial value fluctuates slightly around 0.7 for most HEB mixers even of different volumes, room temperature resistances, and critical temperatures. The critical current degrades sharply vvhile room temperature resistance varies over 1.25.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1435
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	Author	Gao, J.R.; Hiajenius, M.; Yang, Z.Q.; Klapwijk, T.M.; Miao, W.; Shi, S. C.; Voronov, B.; Gortsman, G.
	Title	Direct comparison of the sensitivity of a spiral and a twin-slot antenna coupled HEB mixer at 1.6 THz			Type	Conference Article
	Year	2006	Publication	Proc. 17^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 17^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	59-62
	Keywords	NbN HEB mixers
	Abstract	To make a direct comparison of the sensitivity between a spiral and a twin slot antenna coupled HEB mixer, we designed both types of mixers and fabricated them in a single processing run and on the same wafer. Both mixers have similar dimensions of NbN bridges (1.5-2 pm x0.2 pm). At 1.6 THz we obtained a nearly identical receiver noise temperature from both mixers (only 5% difference), which is in a good agreement with the simulation based on semi analytical models for both antennas. In addition, by using a bandpass filter to reduce the direct detection effect and lowering the bath temperature to 2.4 K, we measured the lowest receiver noise temperature of 700 K at 1.63 THz using the twin-slot antenna mixer.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1436
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	Author	Baselmans, J. J. A.; Baryshev, A.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Voronov, B.; Gol'tsman, G.
	Title	Influence of the direct response on the heterodyne sensitivity of hot electron bolometer mixers			Type	Abstract
	Year	2006	Publication	Proc. 17^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 17^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	81
	Keywords	NbN HEB mixers
	Abstract	We present a detailed experimental study of the direct detection effect in a small volume (0.15pm x lpm) NbN hot electron bolometer mixer. It is a quasioptical mixer with a twin slot antenna designed for 700 GHz and the measurement was done at a LO frequency of 670 GHz. The direct detection effect is characterized by a change in the mixer bias current when switching broadband radiation from a 300 K hot load to a 77 K cold load in a standard Y factor measurement. The result is, depending on the receiver under study, an increase or decrease in the receiver noise temperature. We find that the small signal noise temperature, which is the noise temperature that would be observed without the presence of the direct detection effect, and thus the one that is relevant for an astronomical observation, is 20% lower than the noise temperature obtained using 300 K and 77 K calibration loads. Thus, in our case the direct detection effect reduces the mixer sensitivity. These results are in good agreement with previous measurement at THz frequencies [1]. Other experiments report an increase in mixer sensitivity [2]. To analyze this discrepancy we have designed a separate set of experiments to find out the physical origin of the direct detection effect. Possible candidates are the bias current dependence of the mixer gain and the bias current dependence of the IF match. We measured directly the change in mixer IF match and receiver gain due to the direct detection effect. From these measurements we conclude that the direct detection effect is caused by a combination of bias current reduction when switching form the 77 K to the 300 K load in combination with the bias current dependence of the receiver gain. The bias current dependence of the receiver gain is shown to be mainly caused by the current dependence of the mixer gain. We also find that an increase in receiver sensitivity due to the direct detection effect is only possible if the noise temperature change due to the direct detection is dominated by the mixer-amplifier IF match. [1] J.J.A. Baselmans, A. Baryshev, S.F. Reker, M. Hajenius, J.R. Gao, T.M. Klapwijk, Yu.Vachtomin, S. Maslennikov, S. Antipov, B. Voronov, and G. Gol'tsman., Appl. Phys. Lett. 86, 163503 (2005). [2] S. Svechnokov, A. Verevkin, B. Voronov, E. Menschikov. E. Gershenzon, G. Gol'tsman, 9th Int. Symp. On Space THz. Techn., 45, (1999).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1437
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	Author	Tarkhov, M.; Morozov, D.; Mauskopf, P.; Seleznev, V.; Korneev, A.; Kaurova, N.; Rubtsova, I.; Minaeva, O.; Voronov, B.; Goltsman, G.
	Title	Single photon counting detector for THz radioastronomy			Type	Conference Article
	Year	2006	Publication	Proc. 17^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 17^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	119-122
	Keywords	NbN SSPD, SNSPD
	Abstract	In this paper we present the results of the research on the superconducting NbN-ultrathin-film single- photon detectors (SSPD) which are capable to detect single quanta in middle IR range. The detection mechanism is based on the hotspot formation in quasi-two-dimensional superconducting structures upon photon absorption. Spectral measurements showed that up to 5.7 gm wavelength (52 THz) the SSPD exhibits single-photon sensitivity. Reduction of operation temperature to 1.6 K allowed us to measure quantum efficiency of -4% at 60 THz. Although further decrease of the operation temperature far below 1 K does not lead to any significant increase of quantum efficiency. We expect that the improvement of the SSPD's performance at reduced operation temperature will make SSPD a practical detector with high characteristics for much lower THz frequencies as well.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1438
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	Author	Gao, J. R.; Hajenius, M.; Tichelaar, F. D.; Voronov, B.; Grishina, E.; Klapwijk, T. M.; Gol'tsman, G.; Zorman, C. A.
	Title	Can NbN films on 3C-SiC/Si change the IF bandwidth of hot electron bolometer mixers?			Type	Conference Article
	Year	2006	Publication	Proc. 17^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 17^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	187-189
	Keywords	NbN HEB mixers
	Abstract	We realized ultra thin NbN films sputtered grown on a 3C-SiC/Si substrate. The film with a thickness of 3.5-4.5 nm shows a 1', of 11.8 K, which is the highest I`, observed among ultra thin NbN films on different substrates. The high-resolution transmission electron microscopy (HRTEM) studies show that the film has a monocrystalline structure, confirming the epitaxial growth on the 3C-SiC. Based on a two-temperature model and input parameters from standard NbN films on Si, simulations predict that the new film can increase the IF bandwidth of a HEB mixer by about a factor of 2 in comparison to the standard films. In addition, we find standard NbN films on Si with a T c of 9.4 K have a thickness of around 5.5 nm, being thicker than expected (3.5 nm).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1439
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	Author	Gol'tsman, G.; Maslennikov, S.; Finkel, M.; Antipov, S.; Kaurova, N.; Grishina, E.; Polyakov, S.; Vachtomin, Y.; Svechnikov, S.; Smirnov, K.; Voronov, B.
	Title	Nanostructured ultrathin NbN film as a terahertz hot-electron bolometer mixer			Type	Conference Article
	Year	2006	Publication	Proc. MRS	Abbreviated Journal	Proc. MRS
	Volume	935	Issue		Pages	210 (1 to 6)
	Keywords	NbN HEB mixers
	Abstract	Planar spiral antenna coupled and directly lens coupled NbN HEB mixer structures are studied. An additional MgO buffer layer between the superconducting film and Si substrate is introduced. The buffer layer enables us to increase the gain bandwidth of a HEB mixer due to better acoustic transparency. The gain bandwidth is widened as NbN film thickness decreases and amounts to 5.2 GHz. The noise temperature of antenna coupled mixer is 1300 and 3100 K at 2.5 and 3.8 THz respectively. The structure and composition of NbN films is investigated by X-ray diffraction spectroscopy methods. Noise performance degradation at LO frequencies more than 3 THz is due to the use of a planar antenna and signal loss in contacts between the antenna and the sensitive NbN bridge. The mixer is reconfigured for operation at higher frequencies in a manner that receiver’s noise temperature is only 2300 K (3 times of quantum limit) at LO frequency of 30 THz.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0272-9172	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1440
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	Author	Ryabchun, S.; Tong, C.-yu E.; Blundell, R.; Kimberk, R.; Gol’tsman, G.
	Title	Effect of microwave radiation on the stability of terahertz hot-electron bolometer mixers			Type	Conference Article
	Year	2006	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	6373	Issue		Pages	63730J (1 to 5)
	Keywords	NbN HEB mixers, hot-electron bolometer mixers, stability, Allan variance, LO power fluctuations
	Abstract	We report our studies of the effect of microwave radiation, with a frequency much lower than that corresponding to the energy gap of the superconductor, on the performance of the NbN hot-electron bolometer (HEB) mixer incorporated into a THz heterodyne receiver. It is shown that exposing the HEB mixer to microwave radiation does not result in a significant rise of the receiver noise temperature and degradation of the mixer conversion gain so long as the level of microwave power is small compared to the local oscillator drive. Hence the injection of a small, but controlled amount of microwave radiation enables active compensation of local oscillator power and coupling fluctuations which can significantly degrade the stability of HEB mixer receivers.
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Anwar, M.; DeMaria, A.J.; Shur, M.S.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Terahertz Physics, Devices, and Systems
	Notes				Approved	no
	Call Number				Serial	1441
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	Author	Baselmans, J. J. A.; Baryshev, A.; Reker, S. F.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G.
	Title	Influence of the direct response on the heterodyne sensitivity of hot electron bolometer mixers			Type	Journal Article
	Year	2006	Publication	J. Appl. Phys.	Abbreviated Journal	J. Appl. Phys.
	Volume	100	Issue	8	Pages	084510 (1 to 7)
	Keywords	NbN HEB mixers
	Abstract	We present a detailed experimental study of the direct detection effect in a small volume (0.15μm×1μm×3.5nm) quasioptical NbN phonon cooled hot electron bolometer mixer at 673GHz. We find that the small signal noise temperature, relevant for an astronomical observation, is 20% lower than the noise temperature obtained using 300 and 77K calibration loads. In a separate set of experiments we show that the direct detection effect is caused by a combination of bias current reduction when switching from the 77 to the 300K load in combination with the bias current dependence of the receiver gain. The bias current dependence of the receiver gain is shown to be mainly caused by the current dependence of the mixer gain.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1442
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	Author	Goltsman, G. N.
	Title	Submillimeter superconducting receivers for astronomy, atmospheric studies and other applications			Type	Abstract
	Year	2006	Publication	31nd IRMW / 14th ICTE	Abbreviated Journal	31nd IRMW / 14th ICTE
	Volume		Issue		Pages	177
	Keywords
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Joint 31st International Conference on Infrared Millimeter Waves and 14th International Conference on Teraherz Electronics
	Notes				Approved	no
	Call Number				Serial	1443
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	Author	Kooi, J. W.; Baselmans, J. J. A.; Baryshev, A.; Schieder, R.; Hajenius, M.; Gao, J.R.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G.
	Title	Stability of heterodyne terahertz receivers			Type	Journal Article
	Year	2006	Publication	J. Appl. Phys.	Abbreviated Journal	J. Appl. Phys.
	Volume	100	Issue	6	Pages	064904 (1 to 9)
	Keywords	NbN HEB mixers
	Abstract	In this paper we discuss the stability of heterodyne terahertz receivers based on small volume NbN phonon cooled hot electron bolometers (HEBs). The stability of these receivers can be broken down in two parts: the intrinsic stability of the HEB mixer and the stability of the local oscillator (LO) signal injection scheme. Measurements show that the HEB mixer stability is limited by gain fluctuations with a 1∕f spectral distribution. In a 60MHz noise bandwidth this results in an Allan variance stability time of ∼0.3s. Measurement of the spectroscopic Allan variance between two intermediate frequency (IF) channels results in a much longer Allan variance stability time, i.e., 3s between a 2.5 and a 4.7GHz channel, and even longer for more closely spaced channels. This implies that the HEB mixer 1∕f noise is strongly correlated across the IF band and that the correlation gets stronger the closer the IF channels are spaced. In the second part of the paper we discuss atmospheric and mechanical system stability requirements on the LO-mixer cavity path length. We calculate the mixer output noise fluctuations as a result of small perturbations of the LO-mixer standing wave, and find very stringent mechanical and atmospheric tolerance requirements for receivers operating at terahertz frequencies.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1444
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	Author	Vachtomin, Y. B.; Antipov, S. V.; Maslennikov, S. N.; Smirnov, K. V.; Polyakov, S. L.; Zhang, W.; Svechnikov, S. I.; Kaurova, N. S.; Grishina, E. V.; Voronov, B. M.; Gol’tsman, G. N.
	Title	Quasioptical hot electron bolometer mixers based on thin NBN films for terahertz region			Type	Conference Article
	Year	2006	Publication	Proc. 16th Int. Crimean Microwave and Telecommunication Technology	Abbreviated Journal	Proc. 16th Int. Crimean Microwave and Telecommunication Technology
	Volume	2	Issue		Pages	688-689
	Keywords	NbN HEB mixers
	Abstract	Presented in this paper are the performances of HEB mixers based on 2-3.5 nm thick NbN films integrated with log-periodic spiral antenna. Double side-band receiver noise temperature values are 1300 K and 3100 K at 2.5 THz and at 3.8 THz, respectively. Mixer gain bandwidth is 5.2 GHz. Local oscillator power is 1-3 muW for mixers with different active area
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	Russian	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1445
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	Author	Вахтомин, Ю. Б.; Антипов, С. В.; Масленников, С. Н.; Смирнов, К. В.; Поляков, С. Л.; Чжан, В.; Свечников, С. И.; Каурова, Н. С.; Гришина, Е. В.; Воронов, Б. М.; Гольцман, Г. Н.
	Title	Квазиоптические смесители терагерцового диапазона на основе эффекта разогрева электронов в тонких пленках NbN			Type	Conference Article
	Year	2006	Publication	Proc. 16th Int. Crimean Microwave and Telecommunication Technology	Abbreviated Journal
	Volume	2	Issue		Pages	688-689
	Keywords	NbN HEB mixers
	Abstract	Представлены результаты измерения рактеристик смесителей на эффекте разогрева электронов в тонких сверхпроводниковых пленках NbN. Смесители были изготовлены на основе пленок NbN толщиной 2-3.5 нм осажденных на кремниевую подложку с буферным подсло- ем MgO. Смесительный элемент согласовывался с планар- ной логопериодической спиральной антенной. Лучшее зна- чение шумовой температуры приемника на основе NbN смесителя составило 1300 К и 3100 К на частотах гетеро- дина 2.5 TГц и 3.8 ТГц, соответственно. Максимальное зна- чение полосы преобразования, измеренной на частоте 900 \|Ц, достигло значения 5.2 ГГц для смесителя изготовлен- ного из NbN пленки толщиной 2 нм. Оптимальная мощность Представлены результаты измерения ха- гетеродинного источника составила 1-3 мкВт для смесите- лей с различным объемом смесительного элемента.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	Russian	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes	Duplicated as 1445			Approved	no
	Call Number				Serial	1446
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	Author	Smirnov, K.; Korneev, A.; Minaeva, O.; Divochij, A.; Rubtsova, I.; Antipov, A.; Ryabchun, S.; Okunev, O.; Milostnaya, I.; Chulkova, G.; Voronov, B.; Kaurova, N.; Seleznev, V.; Korotetskaya, Y.; Gol’tsman, G.
	Title	Superconducting single-photon detector for near- and middle IR wavelength range			Type	Conference Article
	Year	2006	Publication	Proc. 16th Int. Crimean Microwave and Telecommunication Technology	Abbreviated Journal	Proc. 16th Int. Crimean Microwave and Telecommunication Technology
	Volume	2	Issue		Pages	684-685
	Keywords	NbN SSPD, SNSPD
	Abstract	Presented in this paper are the results of research of NbN-film superconducting single-photon detector. At 2 K temperature, quantum efficiency in the visible light (0.56 mum) reaches 30-40 %. With the wavelength increase quantum efficiency decreases and comes to 20% at 1.55 mum and 0.02% at 5.6 mum. Minimum dark counts rate is 2times10-4s-1. The jitter of detector is 35 ps. The detector was successfully implemented for integrated circuits non-invasive optical testing. It is also perspective for quantum cryptography systems
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	Russian	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1447
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	Author	Jiang, Ling; Miao, Wei; Zhang, Wen; Li, Ning; Lin, Zhen Hui; Yao, Qi Jun; Shi, Sheng-Cai; Svechnikov, S. I.; Vakhtomin, Y. B.; Antipov, S. V.; Voronov, B. M.; Kaurova, N. S.; Gol'tsman, G. N.
	Title	Characterization of a quasi-optical NbN superconducting HEB mixer			Type	Journal Article
	Year	2006	Publication	IEEE Trans. Microwave Theory Techn.	Abbreviated Journal	IEEE Trans. Microwave Theory Techn.
	Volume	54	Issue	7	Pages	2944-2948
	Keywords	NbN HEB mixers
	Abstract	In this paper, the performance of a quasi-optical NbN superconducting hot-electron bolometer (HEB) mixer, cryogenically cooled by a close-cycled 4-K refrigerator, is thoroughly investigated at 300, 500, and 850 GHz. The lowest receiver noise temperatures measured at the respective three frequencies are 1400, 900, and 1350 K, which can go down to 659, 413, and 529 K, respectively, after correcting the loss and associated noise contribution of the quasi-optical system before the measured superconducting HEB mixer. The stability of the quasi-optical superconducting HEB mixer is also investigated here. The Allan variance time measured with a local oscillator pumping at 500 GHz and an IF bandwidth of 110 MHz is 1.5 s at the dc-bias voltage exhibiting the lowest noise temperature and increases to 2.5 s at a dc bias twice that voltage.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0018-9480	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1448
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	Author	Słysz, W.; Węgrzecki, M.; Bar, J.; Grabiec, P.; Górska, M.; Zwiller, V.; Latta, C.; Bohi, P.; Milostnaya, I.; Minaeva, O.; Antipov, A.; Okunev, O.; Korneev, A.; Smirnov, K.; Voronov, B.; Kaurova, N.; Gol’tsman, G.; Pearlman, A.; Cross, A.; Komissarov, I.; Verevkin, A.; Sobolewski, R.
	Title	Fiber-coupled single-photon detectors based on NbN superconducting nanostructures for practical quantum cryptography and photon-correlation studies			Type	Journal Article
	Year	2006	Publication	Appl. Phys. Lett.	Abbreviated Journal	Appl. Phys. Lett.
	Volume	88	Issue	26	Pages	261113 (1 to 3)
	Keywords	SSPD, SNSPD
	Abstract	We have fabricated and tested a two-channel single-photon detector system based on two fiber-coupled superconducting single-photon detectors (SSPDs). Our best device reached the system quantum efficiency of 0.3% in the 1540-nm telecommunication wavelength with a fiber-to-detector coupling factor of about 30%. The photoresponse consisted of 2.5-ns-wide voltage pulses with a rise time of 250ps and timing jitter below 40ps. The overall system response time, measured as a second-order, photon cross-correlation function, was below 400ps. Our SSPDs operate at 4.2K inside a liquid-helium Dewar, but their optical fiber inputs and electrical outputs are at room temperature. Our two-channel detector system should find applications in practical quantum cryptography and in antibunching-type quantum correlation measurements. The authors would like to thank Dr. Marc Currie for his assistance in early time-resolved photoresponse measurements and Professor Atac Imamoglu for his support. This work was supported by the Polish Ministry of Science under Project No. 3 T11B 052 26 (Warsaw), RFBR 03-02-17697 and INTAS 03-51-4145 grants (Moscow), CRDF Grant No. RE2-2531-MO-03 (Moscow), RE2-2529-MO-03 (Moscow and Rochester), and US AFOSR FA9550-04-1-0123 (Rochester). Additional funding was provided by the grants from the MIT Lincoln Laboratory and BBN Technologies Corp.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1449
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	Author	Milostnaya, I.; Korneev, A.; Rubtsova, I.; Seleznev, V.; Minaeva, O.; Chulkova, G.; Okunev, O.; Voronov, B.; Smirnov, K.; Gol'tsman, G.; Slysz, W.; Wegrzecki, M.; Guziewicz, M.; Bar, J.; Gorska, M.; Pearlman, A.; Kitaygorsky, J.; Cross, A.; Sobolewski, R.
	Title	Superconducting single-photon detectors designed for operation at 1.55-µm telecommunication wavelength			Type	Conference Article
	Year	2006	Publication	J. Phys.: Conf. Ser.	Abbreviated Journal	J. Phys.: Conf. Ser.
	Volume	43	Issue		Pages	1334-1337
	Keywords	NbN SSPD, SNSPD
	Abstract	We report on our progress in development of superconducting single-photon detectors (SSPDs), specifically designed for secure high-speed quantum communications. The SSPDs consist of NbN-based meander nanostructures and operate at liquid helium temperatures. In general, our devices are capable of GHz-rate photon counting in a spectral range from visible light to mid-infrared. The device jitter is 18 ps and dark counts can reach negligibly small levels. The quantum efficiency (QE) of our best SSPDs for visible-light photons approaches a saturation level of ~30-40%, which is limited by the NbN film absorption. For the infrared range (1.55µm), QE is ~6% at 4.2 K, but it can be significantly improved by reduction of the operation temperature to the 2-K level, when QE reaches ~20% for 1.55-µm photons. In order to further enhance the SSPD efficiency at the wavelength of 1.55 µm, we have integrated our detectors with optical cavities, aiming to increase the effective interaction of the photon with the superconducting meander and, therefore, increase the QE. A successful effort was made to fabricate an advanced SSPD structure with an optical microcavity optimized for absorption of 1.55 µm photons. The design consisted of a quarter-wave dielectric layer, combined with a metallic mirror. Early tests performed on relatively low-QE devices integrated with microcavities, showed that the QE value at the resonator maximum (1.55-µm wavelength) was of the factor 3-to-4 higher than that for a nonresonant SSPD. Independently, we have successfully coupled our SSPDs to single-mode optical fibers. The completed receivers, inserted into a liquid-helium transport dewar, reached ~1% system QE for 1.55 µm photons. The SSPD receivers that are fiber-coupled and, simultaneously, integrated with resonators are expected to be the ultimate photon counters for optical quantum communications.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1742-6588	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1450
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	Author	Dauler, E. A.; Kerman, A. J.; Robinson, B. S.; Yang, J. K. W.; Voronov, B. M.; Gol’tsman, G. N.; Berggren, K. K.
	Title	Achieving high counting rates in superconducting nanowire single-photon detectors			Type	Conference Article
	Year	2006	Publication	CLEO/QELS	Abbreviated Journal	CLEO/QELS
	Volume		Issue		Pages	JTuD3 (1 to 2)
	Keywords	SSPD; SNSPD; Detectors; Photodetectors; Quantum optics; Quantum detectors; Photon counting; Photons; Pulse shaping; Quantum communications; Single photon detectors; Superconductors
	Abstract	Kinetic inductance is determined to be the primary limitation to the counting rate of superconducting nanowire single-photon counters. Approaches for overcoming this limitation will be discussed.
	Address
	Corporate Author				Thesis
	Publisher	Optical Society of America	Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies
	Notes				Approved	no
	Call Number				Serial	1451
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	Author	Rosfjord, K. M.; Yang, J. K. W.; Dauler, E. A.; Anant, V.; Berggren, K. K.; Kerman, A. J.; Voronov, B. M.; Gol’tsman, G. N.
	Title	Increased detection efficiencies of nanowire single-photon detectors by integration of an optical cavity and anti-reflection coating			Type	Conference Article
	Year	2006	Publication	CLEO/QELS	Abbreviated Journal	CLEO/QELS
	Volume		Issue		Pages	JTuF2 (1 to 2)
	Keywords	SSPD, SNSPD
	Abstract	We fabricate and test superconducting NbN-nanowire single-photon detectors with an integrated optical cavity and anti-reflection coating. We design the cavity and coating such as to maximize absorption in the NbN film of the detector.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference
	Notes				Approved	no
	Call Number				Serial	1452
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	Author	Kerman, A. J.; Dauler, E. A.; Keicher, W. E.; Yang, J. K. W.; Berggren, K. K.; Gol’tsman, G.; Voronov, B.
	Title	Kinetic-inductance-limited reset time of superconducting nanowire photon counters			Type	Journal Article
	Year	2006	Publication	Appl. Phys. Lett.	Abbreviated Journal	Appl. Phys. Lett.
	Volume	88	Issue	11	Pages	111116 (1 to 3)
	Keywords	NbN SSPD, SNSPD
	Abstract	We investigate the recovery of superconducting NbN-nanowire photon counters after detection of an optical pulse at a wavelength of 1550nm, and present a model that quantitatively accounts for our observations. The reset time is found to be limited by the large kinetic inductance of these nanowires, which forces a tradeoff between counting rate and either detection efficiency or active area. Devices of usable size and high detection efficiency are found to have reset times orders of magnitude longer than their intrinsic photoresponse time. The authors acknowledge D. Oates and W. Oliver (MIT Lincoln Laboratory), S.W. Nam, A. Miller, and R. Hadfield (NIST) and R. Sobolewski, A. Pearlman, and A. Verevkin (University of Rochester) for helpful discussions and technical assistance. This work made use of MIT’s shared scanning-electron-beam-lithography facility in the Research Laboratory of Electronics. This work is sponsored by the United States Air Force under Air Force Contract No. FA8721-05-C-0002. Opinions, interpretations, recommendations and conclusions are those of the authors and are not necessarily endorsed by the United States Government.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1453
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	Author	Kitaygorsky, Jennifer; Komissarov, I.; Jukna, A.; Sobolewski, Roman; Minaeva, O.; Kaurova, N.; Korneev, A.; Voronov, B.; Milostnaya, I.; Gol'Tsman, Gregory
	Title	Nanosecond, transient resistive state in two-dimensional superconducting stripes			Type	Abstract
	Year	2006	Publication	Proc. APS March Meeting	Abbreviated Journal	Proc. APS March Meeting
	Volume		Issue		Pages	H38.13
	Keywords	NbN stripes
	Abstract	We have observed, nanosecond-in-duration, transient voltage pulses, generated across two-dimensional (2-D) NbN stripes (width: 100--500 nm; thickness: 3.5--10 nm) of various lengths (1--500 μm), when the wires were completely isolated from the outside world, biased at currents close to the critical current, and kept at temperatures below the mean-field critical temperature Tco. In 2-D superconducting films, at temperatures below the Kosterlitz-Thouless transition, all vortices are bound and the resistance is zero. However, these vortices can get unbound when a large enough transport current is applied. The latter results in a transient resistive state, which manifests itself as spontaneous, 2.5--8-ns-long voltage pulses with the amplitude corresponding to the unbinding potential of a vortex pair. In our 100-nm-wide stripes, we have also observed the formation of phase slip centers (PSCs) at temperatures close to Tco, and a mixture of PSCs and unbound vortex-antivortex pairs at low temperatures.
	Address	Baltimore, MD
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1454
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	Author	Bell, Matthew; Sergeev, Andrei; Goltsman, Gregory; Bird, Jonathan; Verevkin, Aleksandr
	Title	Transition-edge sensors based on superconducting nanowires			Type	Abstract
	Year	2006	Publication	Proc. APS March Meeting	Abbreviated Journal	Proc. APS March Meeting
	Volume		Issue		Pages	B38.00001
	Keywords	NbN nanowire TES
	Abstract	We present our experimental study of superconducting NbN nanowire-based sensor. The responsivity of the sensor is strongly affected by the superconducting transition width of the nanostructure, which, in turn, is determined by the phase slip centers (PCSs) dynamics. The fluctuations and noise properties of the sensor are also discussed, as well as the devices' behavior at high magnetic fields. The ultimate performance of the sensor and prospects of the devices will be discussed, as well.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1455
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	Author	Yang, Z. Q.; Hajenius, M.; Baselmans, J. J. A.; Gao, J. R.; Voronov, B.; Gol’tsman, G. N.
	Title	Reduced noise in NbN hot-electron bolometer mixers by annealing			Type	Journal Article
	Year	2006	Publication	Supercond. Sci. Technol.	Abbreviated Journal	Supercond. Sci. Technol.
	Volume	19	Issue	4	Pages	L (9 to 12)
	Keywords	NbN HEB mixers
	Abstract	We find that the sensitivity of heterodyne receivers based on superconducting hot-electron bolometers (HEBs) increases by 25–30% after annealing at 85 °C in vacuum. The devices studied are twin-slot antenna coupled mixers with a small NbN bridge of 1 × 0.15 µm2. We show that annealing changes the device properties as reflected in sharper resistive transitions of the complete device, apparently reducing the device-related noise. The lowest receiver noise temperature of 700 K is measured at a local oscillator frequency of 1.63 THz and a bath temperature of 4.3 K.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0953-2048	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1456
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	Author	Hübers, H.-W.; Semenov, A.; Holldack, K.; Schade, U.; Wüstefeld, G.; Gol’tsman, G.
	Title	Time domain analysis of coherent terahertz synchrotron radiation			Type	Journal Article
	Year	2005	Publication	Appl. Phys. Lett.	Abbreviated Journal	Appl. Phys. Lett.
	Volume	87	Issue	18	Pages	184103 (1 to 3)
	Keywords	NbN HEB mixers, applications
	Abstract	The time structure of coherent terahertz synchrotron radiation at the electron storage ring of the Berliner Elektronensynchrotron und Speicherring Gesellschaft has been analyzed with a fast superconducting hot-electron bolometer. The emission from a single bunch of electrons was found to last ∼1500ps at frequencies around 0.4THz, which is much longer than the length of an electron bunch in the time domain (∼5ps). It is suggested that this is caused by multiple reflections at the walls of the beam line. The quadratic increase of the power with the number of electrons in the bunch as predicted for coherent synchrotron radiation and the transition from stable to bursting radiation were determined from a single storage ring fill pattern of bunches with different populations.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1457
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	Author	Milostnaya, I.; Korneev, A.; Minaeva, O.; Rubtsova, I.; Slepneva, S.; Seleznev, V.; Chulkova, G.; Okunev, O.; Smirnov, K.; Voronov, B.; Gol’tsman, G.; Slysz, W.; Kitaygorsky, J.; Cross, A.; Pearlman, A.; Sobolewski, R.
	Title	Superconducting nanostructured detectors capable of single photon counting of mid-infrared optical radiation			Type	Conference Article
	Year	2005	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	5957	Issue		Pages	59570A (1 to 9)
	Keywords	SSPD, SNSPD, single-photon detectors, superconductors, superconducting
	Abstract	We report on our progress in research and development of ultrafast superconducting single-photon detectors (SSPDs) based on ultrathin NbN nanostructures. Our SSPDs were made of the 4-nm-thick NbN films with T_c 11 K, patterned as meander-shaped, 100-nm-wide strips, and covering an area of 10×10 μm². The detectors exploit a combined detection mechanism, where upon a single-photon absorption, a hotspot of excited electrons and redistribution of the biasing supercurrent, jointly produce a picosecond voltage transient signal across the superconducting nanostripe. The SSPDs are typically operated at 4.2 K, but their sensitivity in the infrared radiation range can be significantly improved by lowering the operating temperature from 4.2 K to 2 K. When operated at 2 K, the SSPD quantum efficiency (QE) for visible light photons reaches 30-40%, which is the saturation value limited by the optical absorption of our 4-nm-thick NbN film. With the wavelength increase of the incident photons,the QE of SSPDs decreases significantly, but even at the wavelength of 6 μm, the detector is able to count single photons and exhibits QE of about 10^-2 %. The dark (false) count rate at 2 K is as low as 2x10^-4 s,^-1 which makes our detector essentially a background-limited sensor. The very low dark-count rate results in a noise equivalent power (NEP) below 10^-18WHz^-1/2 for the mid-infrared range (6 μm). Further improvement of the SSPD performance in the mid-infrared range can be obtained by substituting NbN for another, lower-T_c materials with a narrow superconducting gap and low quasiparticles diffusivity. The use of such superconductors should shift the cutoff wavelength below 10 μm.
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Rogalski, A.; Dereniak, E.L.; Sizov, F.F.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Infrared Photoelectronics
	Notes				Approved	no
	Call Number				Serial	1458
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	Author	Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Górska, M.; Latta, C.; Zwiller, V.; Pearlman, A.; Cross, A.; Korneev, A.; Kouminov, P.; Smirnov, K.; Voronov, B.; Gol’tsman, G.; Verevkin, A.; Currie, M.; Sobolewski, R.
	Title	Fiber-coupled quantum-communications receiver based on two NbN superconducting single-photon detectors			Type	Conference Article
	Year	2005	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	5957	Issue		Pages	59571K (1 to 10)
	Keywords	SSPD, SNSPD, single-photon detectors, quantum communication, quantum cryptography, superconductors, infrared optical detectors
	Abstract	We present the design and performance of a novel, two-channel single-photon receiver, based on two fiber-coupled NbN superconducting single-photon detectors (SSPDs). The SSPDs are nanostructured superconducting meanders covering an area of 100 μm² and are known for ultrafast and efficient counting of single, visible-to-infrared photons. Their operation has been explained within a phenomenological hot-electron photoresponse model. Our receiver is intended for fiber-based quantum cryptography and communication systems, operational at near-infrared (NIR) telecommunication wavelengths, λ = 1.3 μm and λ = 1.55 μm. Coupling between the NbN detector and a single-mode optical fiber was achieved using a specially designed, micromechanical photoresist ring, positioned directly over the SSPD active area. The positioning accuracy of the ring was below 1 μm. The receiver with SSPDs was placed (immersed) in a standard liquid-helium transport Dewar and kept without interruption for over two months at 4.2 K. At the same time, the optical fiber inputs and electrical outputs were kept at room temperature. Our best system reached a system quantum efficiency of up to 0.3 % in the NIR radiation range, with the detector coupling efficiency of about 30 %. The response time was measured to be about 250 ps and was limited by our read-out electronics. The measured jitter was close to 35 ps. The presented performance parameters show that our NIR single photon detectors are suitable for practical quantum cryptography and for applications in quantum-correlation experiments.
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Rogalski, A.; Dereniak, E.L.; Sizov, F.F.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Infrared Photoelectronics
	Notes				Approved	no
	Call Number				Serial	1459
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	Author	Bryerton, E.; Percy, R.; Bass, R.; Schultz, J.; Oluleye, O.; Lichtenberger, A.; Ediss, G. A.; Pan, S. K.; Goltsman, G. N.
	Title	Receiver measurements of pHEB beam lead mixers on 3-μm silicon			Type	Conference Article
	Year	2005	Publication	Proc. 30th IRMMW / 13th THz	Abbreviated Journal	Proc. 30th IRMMW / 13th THz
	Volume		Issue		Pages	271-272
	Keywords
	Abstract	We report on receiver noise measurement results of phonon-cooled HEB beam lead mixers on 3 μm thick silicon. This type of ultra-thin mixer chip with integrated beam leads allows easy assembly into a block and holds great promise for array integration. Receiver measurements from 600-720 GHz are presented with a minimum noise temperature of 500 K at 666 GHz. These results verify the mixer performance of the SOI processing techniques allowing for further design and integration of SOI pHEB mixers in receivers operating above 1 THz.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics
	Notes				Approved	no
	Call Number				Serial	1460
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	Author	Chulkova, G.; Milostnaya, I.; Korneev, A.; Minaeva, O.; Rubtsova, I.; Voronov, B.; Okunev, O.; Smirnov, K.; Gol’tsman, G.; Kitaygorsky, J.; Cross, A.; Pearlman, A.; Sobolewski, R.; Slysz, W.
	Title	Superconducting nanostructures for counting of single photons in the infrared range			Type	Conference Article
	Year	2005	Publication	Proc. 2-nd CAOL	Abbreviated Journal	Proc. 2-nd CAOL
	Volume	2	Issue		Pages	100-103
	Keywords	SSPD, SNSPD
	Abstract	We present our studies on ultrafast superconducting single-photon detectors (SSPDs) based on ultrathin NbN nanostructures. Our SSPDs are patterned by electron beam lithography from 4-nm thick NbN film into meander-shaped strips covering square area of 10/spl times/10 /spl mu/m/sup 2/. The advances in the fabrication technology allowed us to produce highly uniform 100-120-nm-wide strips with meander filling factor close to 0.6. The detectors exploit a combined detection mechanism, where upon a single-photon absorption, an avalanche of excited hot electrons and the biasing supercurrent, jointly produce a picosecond voltage transient response across the superconducting nanostrip. The SSPDs are typically operated at 4.2 K, but they have shown that their sensitivity in the infrared radiation range can be significantly improved by lowering the operating temperature from 4.2 K to 2 K. When operated at 2 K, the SSPD quantum efficiency (QE) for visible light photons reaches 30-40%, which is the saturation value limited by optical absorption of our 4-nm-thick NbN film. For 1.55 /spl mu/m photons, QE was /spl sim/20% and decreases exponentially with the increase of the optical wavelength, but even at the wavelength of 6 /spl mu/m the detector remains sensitive to single photons and exhibits QE of about 10/sup -2/%. The dark (false) count rate at 2 K is as low as 2 /spl times/ 10/sup -4/ s/sup -1/, what makes our detector essentially a background-limited sensor. The very low dark-count rate results in the noise equivalent power (NEP) as low as 10/sup -18/ WHz/sup -1/2/ for the mid-infrared range (6 /spl mu/m). Further improvement of the SSPD performance in the mid-infrared range can be obtained by substituting NbN for the other, lower-T/sub c/ superconductors with the narrow superconducting gap and low quasiparticle diffusivity. The use of such materials will shift the cutoff wavelength towards the values even longer than 6 /spl mu/m.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Second International Conference on Advanced Optoelectronics and Lasers
	Notes				Approved	no
	Call Number				Serial	1461
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	Author	Okunev, O.; Chulkova, G.; Milostnaya, I.; Antipov, A.; Smirnov, K.; Morozov, D.; Korneev, A.; Voronov, B.; Gol’tsman, G.; Stysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Gorska, M.; Pearlman, A.; Cross, A.; Kitaygorsky, J.; Sobolewski, R.
	Title	Registration of infrared single photons by a two-channel receiver based on fiber-coupled superconducting single-photon detectors			Type	Conference Article
	Year	2005	Publication	Proc. 2-nd CAOL	Abbreviated Journal	Proc. 2-nd CAOL
	Volume	2	Issue		Pages	282-285
	Keywords	NbN SSPD, SNSPD
	Abstract	Single-photon detectors (SPDs) are the foundation of all quantum communications (QC) protocols. Among different classes of SPDs currently studied, NbN superconducting SPDs (SSPDs) are established as the best devices for ultrafast counting of single photons in the infrared (IR) wavelength range. The SSPDs are nanostructured, 100 /spl mu/m/sup 2/ in total area, superconducting meanders, patterned by electron lithography in ultra-thin NbN films. Their operation has been explained within a phenomenological hot-electron photoresponse model. We present the design and performance of a novel, two-channel SPD receiver, based on two fiber-coupled NbN SSPDs. The receivers have been developed for fiber-based QC systems, operational at 1.3 /spl mu/m and 1.55 /spl mu/m telecommunication wavelengths. They operate in the temperature range from 4.2 K to 2 K, in which the NbN SSPDs exhibit their best performance. The receiver unit has been designed as a cryostat insert, placed inside a standard liquid-helium storage dewar. The input of the receiver consists of a pair of single-mode optical fibers, equipped with the standard FC connectors and kept at room temperature. Coupling between the SSPD and the fiber is achieved using a specially designed, precise micromechanical holder that places the fiber directly on top of the SSPD nanostructure. Our receivers achieve the quantum efficiency of up to 7% for near-IR photons, with the coupling efficiency of about 30%. The response time was measured to be <300 ps and it was limited by our read-out electronics. The jitter of fiber-coupled SSPDs is <35 ps and their dark-count rate is below 1 s/sup -1/. The presented performance parameters show that our single-photon receivers are fully applicable for quantum-correlation-type QC systems, including practical quantum cryptography.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Second International Conference on Advanced Optoelectronics and Lasers
	Notes				Approved	no
	Call Number				Serial	1462
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	Author	Morozov, D. V.; Smirnov, K. V.; Smirnov, A. V.; Lyakhov, V. A.; Goltsman, G. N.
	Title	A millimeter-submillimeter phonon-cooled hot-electron bolometer mixer based on two-dimensional electron gas in an AlGaAs/GaAs heterostructure			Type	Journal Article
	Year	2005	Publication	Semicond.	Abbreviated Journal	Semicond.
	Volume	39	Issue	9	Pages	1082-1086
	Keywords	2D electron gas, AlGaAs/GaAs heterostructures, mixers
	Abstract	Experimental results obtained by studying the main characteristics of a millimeter-submillimeter wave mixer based on the hot-electron effect in a two-dimensional electron gas in a AlGaAs/GaAs heterostructure with a phonon-scattering cooling mechanism for charge carriers are reported. The gain bandwidth of the mixer is 4 GHz, the internal conversion losses are 13 dB, and the optimum local-oscillator power is 0.5 μW (for a mixer area of 1 μm2). It is shown that a millimeter-submillimeter-wave receiver with a noise temperature of 1900 K can be developed on the basis of a AlGaAs/GaAs mixer. This mixer also appears to be promising for use in array receiver elements.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1063-7826	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1463
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	Author	Loudkov, D.; Tong, C.-Y. E.; Blundell, R.; Kaurova, N.; Grishina, E.; Voronov, B.; Gol’tsman, G.
	Title	An investigation of the performance of the superconducting HEB mixer as a function of its RF embedding impedance			Type	Journal Article
	Year	2005	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	15	Issue	2	Pages	472-475
	Keywords	waveguide NbN HEB mixers
	Abstract	We have conducted an investigation of the optimal embedding impedance for a waveguide superconducting hot-electron bolometric (HEB) mixer. Three mixer chip designs for 800 GHz, offering nominal embedding resistances of 70 /spl Omega/, 35 /spl Omega/, and 15 /spl Omega/, have been developed. We used both High Frequency Structure Simulator (HFSS) software and scale model impedance measurements in the design process. We subsequently fabricated HEB mixers to these designs using 3-4 nm thick NbN thin film. Receiver noise temperature measurements and Fourier Transform Spectrometer (FTS) scans were performed to determine the optimal combination of embedding impedance and normal-state resistance for a 50 Ohm IF load impedance. A receiver noise temperature of 440 K was measured at a local oscillator frequency 850 GHz for a mixer with normal state resistance of 62 /spl Omega/ incorporated into a circuit offering a nominal embedding impedance of 70 /spl Omega/. We conclude from our data that, for low noise operation, the normal state resistance of the HEB mixer element should be close to the embedding impedance of the mixer mount.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number	1439677			Serial	1464
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	Author	Pearlman, A.; Cross, A.; Slysz, W.; Zhang, J.; Verevkin, A.; Currie, M.; Korneev, A.; Kouminov, P.; Smirnov, K.; Voronov, B.; Gol’tsman, G.; Sobolewski, R.
	Title	Gigahertz counting rates of NbN single-photon detectors for quantum communications			Type	Journal Article
	Year	2005	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	15	Issue	2	Pages	579-582
	Keywords	NbN SSPD, SNSPD
	Abstract	We report on the GHz counting rate and jitter of our nanostructured superconducting single-photon detectors (SSPDs). The devices were patterned in 4-nm-thick and about 100-nm-wide NbN meander stripes and covered a 10-/spl mu/m/spl times/10-/spl mu/m area. We were able to count single photons at both the visible and infrared telecommunication wavelengths at rates of over 2 GHz with a timing jitter of below 18 ps. We also present the model for the origin of the SSPD switching dynamics and jitter, based on the time-delay effect in the phase-slip-center formation mechanism during the detector photoresponse process. With further improvements in our readout electronics, we expect that our SSPDs will reach counting rates of up to 10 GHz. An integrated quantum communications receiver based on two fiber-coupled SSPDs and operating at 1550-nm wavelength is also presented.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1558-2515	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1465
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	Author	Yang, J. K. W.; Dauler, E.; Ferri, A.; Pearlman, A.; Verevkin, A.; Gol’tsman, G.; Voronov, B.; Sobolewski, R.; Keicher, W. E.; Berggren, K. K.
	Title	Fabrication development for nanowire GHz-counting-rate single-photon detectors			Type	Journal Article
	Year	2005	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	15	Issue	2	Pages	626-630
	Keywords	NbN SSPD, SNSPD
	Abstract	We have developed a fabrication process for GHz-counting-rate, single-photon, high-detection-efficiency, NbN, nanowire detectors. We have demonstrated two processes for the device patterning, one based on the standard polymethylmethacrylate (PMMA) organic positive-tone electron-beam resist, and the other based on the newer hydrogen silsesquioxane (HSQ) negative-tone spin-on-glass resist. The HSQ-based process is simple and robust, providing high resolution and the prospect of high fill-factors. Initial testing results show superconductivity in the films, and suggest that the devices exhibit photosensitivity.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1558-2515	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1466
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	Author	Korneev, A.; Matvienko, V.; Minaeva, O.; Milostnaya, I.; Rubtsova, I.; Chulkova, G.; Smirnov, K.; Voronov, V.; Gol’tsman, G.; Slysz, W.; Pearlman, A.; Verevkin, A.; Sobolewski, R.
	Title	Quantum efficiency and noise equivalent power of nanostructured, NbN, single-photon detectors in the wavelength range from visible to infrared			Type	Journal Article
	Year	2005	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	15	Issue	2	Pages	571-574
	Keywords	NbN SSPD, SNSPD, QE, NEP
	Abstract	We present our studies on the quantum efficiency (QE) and the noise equivalent power (NEP) of the latest-generation, nanostructured, superconducting, single-photon detectors (SSPDs) in the wavelength range from 0.5 to 5.6 /spl mu/m, operated at temperatures in the 2.0- to 4.2-K range. Our detectors are designed as 4-nm-thick and 100-nm-wide NbN meander-shaped stripes, patterned by electron-beam lithography and cover a 10/spl times/10-/spl mu/m/sup 2/ active area. The best-achieved QE at 2.0 K for 1.55-/spl mu/m photons is 17%, and QE for 1.3-/spl mu/m infrared photons reaches its saturation value of /spl sim/30%. The SSPD NEP at 2.0 K is as low as 5/spl times/10/sup -21/ W/Hz/sup -1/2/. Our nanostructured SSPDs, operated at 2.0 K, significantly outperform their semiconducting counterparts, and, together with their GHz counting rate and picosecond timing jitter, they are devices-of-choice for practical quantum key distribution systems and free-space (even interplanetary) quantum optical communications.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1558-2515	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1467
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	Author	Baubert, J.; Salez, M.; Merkel, H.; Pons, P.; Cherednichenko, S.; Lecomte, B.; Drakinsky, V.; Goltsman, G.; Leone, B.
	Title	IF gain bandwidth of membrane-based NbN hot electron bolometers for SHAHIRA			Type	Journal Article
	Year	2005	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	15	Issue	2	Pages	507-510
	Keywords	NbN HEB mixers, applications
	Abstract	SHAHIRA (Submm Heterodyne Array for HIgh-speed Radio Astronomy) is a project supported by the European Space Agency (ESA) and is designed to fly on the SOFIA observatory. A quasi-optic design has been chosen for 2.5/2.7 THz and 4.7 THz, for hydroxyde radical OH, deuterated hydrogen HD and neutral atomic oxygen OI lines observations. Hot electron bolometers (HEBs) have been processed on 1 /spl mu/m thick SiO/sub 2//Si/sub 3/N/sub 4/ stress-less membranes. In this paper we analyse the intermediate frequency (IF) gain bandwidth from the theoretical point of view, and compare it to measurements.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1558-2515	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1468
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	Author	Jiang, L.; Li, J.; Zhang, W.; Yao, Q. J.; Lin, Z. L.; Shi, S. C.; Vachtomin, Y. B.; Antipov, S. V.; Svechnikov, S. I.; Voronov, B. M.; Goltsman, G. N.
	Title	Characterization of NbN HEB mixers cooled by a close-cycled 4 Kelvin refrigerator			Type	Journal Article
	Year	2005	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	15	Issue	2	Pages	511-513
	Keywords	NbN HEB mixers
	Abstract	It is quite beneficial to operate superconducting hot-electron-bolometer (HEB) mixers with a close-cycled 4 Kelvin refrigerator for real applications such as astronomy and atmospheric research. In this paper, a phononcooled NbN HEB mixer (quasioptical type) is thoroughly characterized under such a cooling circumstance. The effects of mechanical vibration, electrical interference, and temperature fluctuation of a two-stage Gifford-McMahon 4 Kelvin refrigerator upon the characteristics of the phononcooled NbN HEB mixer are investigated in particular. Detailed measurement results are presented.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1558-2515	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1469
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	Author	Zhang, W.; Jiang, L.; Lin, Z. H.; Yao, Q. J.; Li, J.; Shi, S. C.; Svechnikov, S. I.; Vachtomin, Yu. B.; Antipov, S. V.; Voronov, B. M.; Kaurova, N. S.; Gol'tsman, G. N.
	Title	Development of a quasi-optical NbN superconducting HEB mixer			Type	Conference Article
	Year	2005	Publication	Proc. 16^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 16^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	209-213
	Keywords	NbN HEB mixers
	Abstract	In this paper, we report the performance of a quasi-optical NbN superconducting HEB (hot electron bolometer) mixer measured at 500 and 850GHz. The quasi-optical NbN superconducting HEB mixer is cryogenically cooled by a 4-K close-cycled refrigerator. Measured receiver noise temperature at 850 and 500GHz are 3000K and 2500K respectively with wire grid as beamsplitter, while the lowest receiver noise temperature is found to be approximately 1200K with Mylar film. The theoretical receiver noise temperature (taking into account the elliptical polarization of log-spiral antenna) is consistent with measured one. The receiver noise temperature and conversion gain with 15-μm Mylar film as the beamsplitter at 500GHz are thoroughly investigated for different LO pumping levels and dc biases. The stability of the mixer’s IF output power is also demonstrated.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1470
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	Author	Yang, Z. Q.; Hajenius, M.; Baselmans, J. J. A.; Gao, J.R.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G.
	Title	Improved sensitivity of NbN hot electron bolometer mixers by vacuum baking			Type	Conference Article
	Year	2005	Publication	Proc. 16^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 16^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	222-225
	Keywords	NbN HEB mixer
	Abstract	We find that the sensitivity of heterodyne receivers based on superconducting hot-electron bolometer (HEB) in- creases by 25 − 30% after baking at 85 o C and in a high vacuum. The devices studied are twin-slot antenna coupled HEB mixers with a small NbN bridge of 1×0.15 μm 2 . The mixer noise temperature, gain, and resistance versus temperature curve of a HEB before and after baking are compared and analyzed. We show that baking reduces the intrinsic noise of the mixer by 37 % and makes the superconducting transition of the bridge and the contacts sharper. We argue that the reduction of the noise is due to the improvement of the transparency of the contact/film interface. The lowest receiver noise temperature of 700 K is measured at a local oscillator frequency of 1.63 THz and a bath temperature of 4.3 K.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1471
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	Author	Loudkov, D.; Tong, C.-Y.E.; Blundell, R.; Kaurova, N.; Grishina, E.; Voronov, B.; Gol’tsman, G.
	Title	An investigation of the performance of the waveguide superconducting HEB mixer at different RF embedding impedances			Type	Conference Article
	Year	2005	Publication	Proc. 16^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 16^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	226-229
	Keywords	waveguide NbN HEB mixers
	Abstract	We have conducted an investigation of the performance of superconducting hot-electron bolometric (HEB) mixer at 800 GHz as a function of the embedding impedance of the waveguide embedding circuit. Using a single half-height mixer block, we have developed three different mixer chip configurations, offering nominal embedding resistances of 70, 35, and 15 Ohms. Both the High Frequency Structure Simulator (HFSS) software and scaled model impedance measurements were employed in the design process. Two batches of HEB mixers were fabricated to these designs using 3-4 nm thick NbN thin film. The mixers were characterized through receiver noise temperature measurements and Fourier Transform Spectrometer (FTS) scans. Briefly, a minimum receiver noise temperature of 440 K was measured at a local oscillator frequency 850 GHz for a mixer of normal state resistance 62 Ohms incorporated into a circuit offering a nominal embedding impedance of 70 Ohms. We conclude from our data that, for low noise operation, the normal state resistance of the HEB mixer element should be close to that of the embedding impedance of the mixer mount.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1472
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	Author	Loudkov, D.; Tong, C.-Y. E.; Marrone, D. P.; Ryabchun, S.; Paine, S. N.; Blundell, R.
	Title	Transmission measurements of infrared filters for low-noise terahertz receiver applications			Type	Conference Article
	Year	2005	Publication	Proc. 16^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 16^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	354-357
	Keywords	FTS, Zitex, alkali halide, crystalline quartz, Parylene, polyethylene, IR filters, transmission, THz applications
	Abstract	Infrared (IR) filters are very important to the efficient operation of cryogenic receivers. Usually, such filters are mounted on the radiation shield of the cryostat to reduce the heat load to the 4 K stage. Insufficient filtering may cause the temperature of the mixing element in a receiver to be excessively warm, leading to degradation in sensitivity. These filters should be effective in blocking the room temperature IR radiation from outside the cryostat, yet should be transparent across the desired signal frequency band. In the Terahertz frequency range, which is close to the infrared, it is difficult to find an inexpensive low- loss material that can provide the required IR blocking capacity. We present transmission measurements, made using a Fourier Transform Spectrometer (FTS), of a number of potential infrared filters between 0.4 and 1.6 THz. The filters tested include the widely-used, Teflon-based, Zitex-A and Zitex-G films, alkali halide based infrared filter, and crystalline quartz coated with Parylene, and polyethylene films.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1473
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	Author	Edward Tong, C.-Y.; Loudkov, Denis N.; Paine, Scott N.; Marrone, Dan P.; Blundell, Raymond
	Title	Vector measurement of the beam pattern of a 1.5 THz superconducting HEB receiver			Type	Conference Article
	Year	2005	Publication	Proc. 16^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 16^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	453-456
	Keywords	NbTiN HEB mixers
	Abstract	Near-field vector beam pattern of the 1.5 THz superconducting Hot Electron Bolometer (HEB) receiver currently in operation in Northern Chile has been performed in our laboratory. Using an open waveguide probe, we have mapped both the amplitude and phase of the beam emerging from our 1.5 THz HEB receiver package, across a number of planes along the line of propagation of the radio-beam. With an integration time of about 100 ms per point, a signal-to-noise ratio of about 25 dB was achieved for a beam waist of 3.5 mm. These measurements have proved to be invaluable in achieving good alignment between the cryostat housing the HEB mixer and the remainder of the receiver and telescope optics. The accuracy of our beam measurement is estimated to be ±0.2 mm in position and ±5 arc minutes in angular displacement.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1474
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	Author	Baryshev, A.; Baselmans, J. J. A.; Reker, S. F.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Vachtomin, Yu.; Maslennikov, S.; Antipov, S.; Voronov, B.; Gol'tsman, G.
	Title	Direct detection effect in hot electron bolometer mixers			Type	Abstract
	Year	2005	Publication	Proc. 16^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 16^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	463-464
	Keywords	NbN HEB mixers, effect of direct detection, direct detection effect
	Abstract	NbN phonon cooled hot electron bolometer (HEB) mixers are currently the most sensitive heterodyne detectors at frequencies above 1.2 THz. They combine a good sensitivity (8-15 times the quantum limit), an IF bandwidth of the order of 4-6 GHz and a wide RF bandwidth from 0.7-5.2 THz. However, for use in a space based observatory, such as Herschel, it is of vital importance that the Local Oscillator (LO) power requirement of the mixer is compatible with the low output power of present day THz LO sources. This can be achieved by reducing the mixer volume and critical current. However, the large RF bandwidth and low LO power requirement of such a mixer result in a direct detection effect, characterized by a change in the bias current of the HEB when changing the RF signal from a black body load at 300 K to one at 77 K. As a result the measured sensitivity using a 300 K and 77 K calibration load differs significantly from the small signal sensitivity relevant for astronomical observations. In this article we describe a set of dedicated experiments to characterize the direct detection effect for a small volume quasi-optical NbN phonon cooled HEB mixer. We measure the direct detection effect in a small volume (0.15 μm · 1 μm · 3.5 nm) quasi- optical NbN phonon cooled HEB mixer at 1.6 THz. We found that the small signal sensitivity of the receiver is underestimated by approximately 35% due to the direct detection effect and that the optimal operating point is shifted to higher bias voltages when using calibration loads of 300 K and 77 K. Using a 200 GHz wide band-pass filter at the 4.2 K the direct detection effect virtually disappears. Heterodyne response measurements using water vapor absorption line in a gas cell confirms the existence and a magnitude of a direct detection effect. We also propose a theoretical explanation using uniform electron heating model. This direct detection effect has important implications for the calibration procedure of these receivers in real telescope systems. We are developing Nb HEBs for a large-format, diffusion-cooled hot electron bolometer (HEB) array submillimeter camera. The goal is to produce a 64 pixel array together with the University of Arizona to be used on the HHT on Mt Graham. It is designed to detect in the 850 GHz atmospheric window. We have fabricated Nb HEBs using a new angle- deposition process, which had previously produced high quality Nb-Au bilayer HEB devices at Yale. [1] We have characterized these devices using heterodyne mixing at ~30 GHz to compare to 345 GHz tests at the University of Arizona. We can also directly compare our Nb HEB mixers to SIS mixers in this same 345 GHz system. This allows us to rigorously calibrate the system’s losses and extract the mixer noise temperature in a well characterized mixer block, before undertaking the 850 GHz system. Here we give a report on the initial devices we have fabricated and characterized. * Department of Applied Physics, Yale University ** Department of Astronomy, University of Arizona [1] Applied Physics Letters 84, Number 8; p.1404-7, Feb 23 (2004)
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1475
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	Author	Gol'tsman, G.; Korneev, A.; Minaeva, O.; Rubtsova, I.; Milostnaya, I.; Chulkova, G.; Voronov, B.; Smirnov, K.; Seleznev, V.; Słysz, W.; Kitaygorsky, J.; Cross, A.; Pearlman, A.; Sobolewski, Roman
	Title	Superconducting nanostructured detectors capable of single-photon counting in the THz range			Type	Conference Article
	Year	2005	Publication	Proc. 16^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 16^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	555-557
	Keywords	NbN SSPD, SNSPD
	Abstract	We present the results of the NbN superconducting single-photon detector sensitivity measurement in the visible to mid-IR range. For visible and near IR light (0.56 — 1.3μm wavelengths) the detector exhibits 30% quantum efficiency saturation value limited by the NbN film absorption and extremely low level of dark counts (2x10 -4 s -1). The detector manifested single-photon counting up to 6 μm wavelength with the quantum efficiency reaching 10 -2 % at 5.6 μm and 3 K temperature.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1476
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	Author	Goltsman, G.; Korneev, A.; Minaeva, O.; Rubtsova, I.; Chulkova, G.; Milostnaya, I.; Smirnov, K.; Voronov, B.; Lipatov, A. P.; Pearlman, A. J.; Cross, A.; Slysz, W.; Verevkin, A. A.; Sobolewski, R.
	Title	Advanced nanostructured optical NbN single-photon detector operated at 2.0 K			Type	Conference Article
	Year	2005	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	5732	Issue		Pages	520-529
	Keywords	NbN SSPD, SNSPD
	Abstract	We present our studies on quantum efficiency (QE), dark counts, and noise equivalent power (NEP) of the latest generation of nanostructured NbN superconducting single-photon detectors (SSPDs) operated at 2.0 K. Our SSPDs are based on 4 nm-thick NbN films, patterned by electron beam lithography as highly-uniform 100÷120-nm-wide meander-shaped stripes, covering the total area of 10x10 μm² with the meander filling factor of 0.7. Advances in the fabrication process and low-temperature operation lead to QE as high as 30-40% for visible-light photons (0.56 μm wavelength)-the saturation value, limited by optical absorption of the NbN film. For 1.55 μm photons, QE was 20% and decreased exponentially with the wavelength reaching 0.02% at the 5-μm wavelength. Being operated at 2.0-K temperature the SSPDs revealed an exponential decrease of the dark count rate, what along with the high QE, resulted in the NEP as low as 5x10^-21 W/Hz^-1/2, the lowest value ever reported for near-infrared optical detectors. The SSPD counting rate was measured to be above 1 GHz with the pulse-to-pulse jitter below 20 ps. Our nanostructured NbN SSPDs operated at 2.0 K significantly outperform their semiconducting counterparts and find practical applications ranging from noninvasive testing of CMOS VLSI integrated circuits to ultrafast quantum communications and quantum cryptography.
	Address
	Corporate Author				Thesis
	Publisher	Spie	Place of Publication		Editor	Razeghi, M.; Brown, G.J.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Quantum Sensing and Nanophotonic Devices II
	Notes				Approved	no
	Call Number				Serial	1478
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	Author	Gol'tsman, G. N.; Korneev, A.; Rubtsova, I.; Milostnaya, I.; Chulkova, G.; Minaeva, O.; Smirnov, K.; Voronov, B.; Słysz, W.; Pearlman, A.; Verevkin, A.; Sobolewski, R.
	Title	Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications			Type	Journal Article
	Year	2005	Publication	Phys. Stat. Sol. (C)	Abbreviated Journal	Phys. Stat. Sol. (C)
	Volume	2	Issue	5	Pages	1480-1488
	Keywords	NbN SSPD, SNSPD
	Abstract	We present our progress on the research and development of NbN superconducting single‐photon detectors (SSPD's) for ultrafast counting of near‐infrared photons for secure quantum communications. Our SSPD's operate in the quantum detection mode based on the photon‐induced hotspot formation and subsequent development of a transient resistive barrier across an ultrathin and submicron‐width superconducting stripe. The devices are fabricated from 4‐nm‐thick NbN films and kept in the 4.2‐ to 2‐K temperature range. The detector experimental quantum efficiency in the photon‐counting mode reaches above 40% for the visible light and up to 30% in the 1.3‐ to 1.55‐µm wavelength range with dark counts below 0.01 per second. The experimental real‐time counting rate is above 2 GHz and is limited by our readout electronics. The SSPD's timing jitter is below 18 ps, and the best‐measured value of the noise‐equivalent power (NEP) is 5 × 10–21 W/Hz1/2 at 1.3 µm. In terms of quantum efficiency, timing jitter, and maximum counting rate, our NbN SSPD's significantly outperform semiconductor avalanche photodiodes and photomultipliers in the 1.3‐ to 1.55‐µm range.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1610-1634	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1479
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	Author	Gao, J. R.; Hajenius, M.; Baselmans, J. J. A.; Yang, Z. Q.; Baryshev, A. M.; Barends, R.; Klapwijk, T. M.; Voronov, B.; Gol'tsman, G.; Callaos, N.
	Title	Twin-slot antenna coupled NbN hot electron bolometer mixers for space applications			Type	Conference Article
	Year	2005	Publication	Proc. 9-th WMSCI	Abbreviated Journal	Proc. 9-th WMSCI
	Volume	9	Issue		Pages	148-153
	Keywords	NbN HEB mixers
	Abstract
	Address
	Corporate Author				Thesis
	Publisher	International Institute of Informatics and Systemics	Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN	9806560639, 9789806560635	Medium
	Area		Expedition		Conference	9th World Multi-Conference on Systemics, Cybernetics and Informatics
	Notes				Approved	no
	Call Number				Serial	1480
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	Author	Słysz, W.; Węgrzecki, M.; Bar, J.; Grabiec, P.; Gol'tsman, G. N.; Verevkin, A.; Sobolewski, R.
	Title	NbN superconducting single-photon detector coupled with a communication fiber			Type	Journal Article
	Year	2005	Publication	Elektronika : konstrukcje, technologie, zastosowania	Abbreviated Journal
	Volume	46	Issue	6	Pages	51-52
	Keywords	NbN SSPD, SNSPD
	Abstract	We present novel superconducting single-photon detectors (SSPDs), based on ultrathin NbN films, designed for fiber-based quantum communications (lambda = 1.3 žm and 1.55 žm). For fiber-based operation, our SSPDs contain a special micromechanical construction integrated with the NbN structure, which enables efficient and mechanically very stabile fiber coupling. The detectors combine GHz counting rate, high quantum efficiency and very low level of dark counts. At 1.3 – 1.55 žm wavelength range our detector exhibits a quantum efficiency up to 10%.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	Polish	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1481
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	Author	Jiang, L.; Zhang, W.; Yao, Q. J.; Lin, Z. H.; Li, J.; Shi, S. C.; Svechnikov, S. I.; Vachtomin, Y. B.; Antipov, S. V.; Voronov, B. M.; Kaurova, N. S.; Gol'tsman, G. N.
	Title	Characterization of a quasi-optical NbN superconducting hot-electron bolometer mixer			Type	Conference Article
	Year	2005	Publication	Proc. PIERS	Abbreviated Journal	Proc. PIERS
	Volume	1	Issue	5	Pages	587-590
	Keywords	NbN HEB mixers
	Abstract	In this paper, we report the performance of a quasi-optical NbN superconducting HEB (hot electron bolome-ter) mixer measured at 500 GHz. The quasi-optical NbN superconducting HEB mixer is cryogenically cooled bya 4-K close-cycled refrigerator. Its receiver noise temperature and conversion gain are thoroughly investigatedfor different LO pumping levels and dc biases. The lowest receiver noise temperature is found to be approxi-mately 1200 K, and reduced to about 445 K after correcting theloss of the measurement system. The stabilityof the mixer’s IF output power is also demonstrated.
	Address	Hangzhou, China
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1931-7360	ISBN		Medium
	Area		Expedition		Conference	Progress In Electromagnetics Research Symposium
	Notes				Approved	no
	Call Number				Serial	1482
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	Author	Hubers, H.-W.; Semenov, A.; Richter, H.; Schwarz, M.; Gunther, B.; Smirnov, K.; Gol’tsman, G.; Voronov, B.
	Title	Heterodyne receiver for 3-5 THz with hot-electron bolometer mixer			Type	Conference Article
	Year	2004	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	5498	Issue		Pages	579-586
	Keywords	NbN HEB mixers
	Abstract	Heterodyne receivers for applications in astronomy and planetary research need quantum limited sensitivity. In instruments which are currently build for SOFIA and Herschel superconducting hot electron bolometers (HEB) will be used to achieve this goal at frequencies above 1.4 THz. The local oscillator and the mixer are the most critical components for a heterodyne receiver operating at 3-5 THz. The design and performance of an optically pumped THz gas laser optimized for this frequency band will be presented. In order to optimize the performance for this frequency hot electron bolometer mixers with different in-plane dimensions and logarithmic-spiral feed antennas have been investigated. Their noise temperatures and beam patterns were measured. Above 3 THz the best performance was achieved with a superconducting bridge of 2.0 x 0.2 Î¼m² incorporated in a logarithmic spiral antenna. The DSB noise temperatures were 2700 K, 4700 K and 6400 K at 3.1 THz, 4.3 THz and 5.2 THz, respectively. The results demonstrate that the NbN HEB is very well suited as a mixer for THz heterodyne receivers up to at least 5 THz.
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Zmuidzinas, J.; Holland, W.S.; Withington, S.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Millimeter and Submillimeter Detectors for Astronomy II
	Notes				Approved	no
	Call Number				Serial	1483
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	Author	Meledin, D. V.; Marrone, D. P.; Tong, C.-Y. E.; Gibson, H.; Blundell, R.; Paine, S. N.; Papa, D.C.; Smith, M.; Hunter, T. R.; Battat, J.; Voronov, B.; Gol'tsman, G.
	Title	A 1-THz superconducting hot-electron-bolometer receiver for astronomical observations			Type	Journal Article
	Year	2004	Publication	IEEE Trans. Microwave Theory Techn.	Abbreviated Journal	IEEE Trans. Microwave Theory Techn.
	Volume	52	Issue	10	Pages	2338-2343
	Keywords	NbN HEB mixer, applications
	Abstract	In this paper, we describe a superconducting hot-electron-bolometer mixer receiver developed to operate in atmospheric windows between 800-1300 GHz. The receiver uses a waveguide mixer element made of 3-4-nm-thick NbN film deposited over crystalline quartz. This mixer yields double-sideband receiver noise temperatures of 1000 K at around 1.0 THz, and 1600 K at 1.26 THz, at an IF of 3.0 GHz. The receiver was successfully tested in the laboratory using a gas cell as a spectral line test source. It is now in use on the Smithsonian Astrophysical Observatory terahertz test telescope in northern Chile.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0018-9480	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1484
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	Author	Slysz, W.; Wegrzecki, M.; Papis, E.; Gol'tsman, G. N.; Verevkin, A.; Sobolewski, R.
	Title	A method of optimization of the NbN superconducting single-photon detector			Type	Miscellaneous
	Year	2004	Publication	INIS	Abbreviated Journal	INIS
	Volume	36	Issue	27	Pages	1-2
	Keywords	NbN SSPD, SNSPD
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	5-th International Symposium Ion Implantation and Other Applications of Ions and Electrons, ION
	Notes	Reference num. 36060124			Approved	no
	Call Number				Serial	1485
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	Author	Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Gol'tsman, G. N.; Verevkin, M.; Sobolewski, R.
	Title	NbN superconducting single-photon detectors coupled with a communication fiber			Type	Miscellaneous
	Year	2004	Publication	INIS	Abbreviated Journal	INIS
	Volume	37	Issue	2	Pages	1-2
	Keywords	NbN SSPD, SNSPD
	Abstract
	Address	Stare Jablonki, Poland
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	8-th Electron Technology Conference ELTE
	Notes				Approved	no
	Call Number				Serial	1486
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	Author	Maslennikov, S. N.; Morozov, D. V.; Ozhegov, R. V.; Smirnov, K. V.; Okunev, O. V.; Gol’tsman, G. N.
	Title	Imaging system for submillimeter wave range based on AlGaAs/GaAs hot electron bolometer mixers			Type	Conference Article
	Year	2004	Publication	Proc. 5-th MSMW	Abbreviated Journal	Proc. 5-th MSMW
	Volume	2	Issue		Pages	558-560
	Keywords	AlGaAs/GaAs HEB mixers
	Abstract	Electromagnetic radiation of the submillimeter (SMM) range is dispersed and absorbed significantly less than infrared (IR) radiation when passing through different objects. That is the reason for the development of an SMM imaging system. In this paper, we discuss the design of an SMM heterodyne imager, based on a matrix of AlGaAs/GaAs heterostructure hot electron bolometer mixers (HEB) with relatively high (about 77 K) operating temperature. The predicted double side band (DSB) noise temperature is about 1000 K and optimal local oscillator (LO) power is about 1 /spl mu/W for such mixers, which seems to be quite prospective for an SMM heterodyne imager.
	Address	Kharkov, Ukraine
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	The Fifth International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter, and Submillimeter Waves (IEEE Cat. No.04EX828)
	Notes				Approved	no
	Call Number				Serial	1487
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	Author	Verevkin, A.; Pearlman, A.; Slysz, W.; Zhang, J.; Currie, M.; Korneev, A.; Chulkova, G.; Okunev, O.; Kouminov, P.; Smirnov, K.; Voronov, B.; Gol'tsman, G. N.; Sobolewski, R.
	Title	Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications			Type	Journal Article
	Year	2004	Publication	J. Modern Opt.	Abbreviated Journal	J. Modern Opt.
	Volume	51	Issue	9-10	Pages	1447-1458
	Keywords	NbN SSPD, SNSPD
	Abstract	The paper reports progress on the design and development of niobium-nitride, superconducting single-photon detectors (SSPDs) for ultrafast counting of near-infrared photons for secure quantum communications. The SSPDs operate in the quantum detection mode, based on photon-induced hotspot formation and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-width superconducting stripe. The devices are fabricated from 3.5 nm thick NbN films and kept at cryogenic (liquid helium) temperatures inside a cryostat. The detector experimental quantum efficiency in the photon-counting mode reaches above 20% in the visible radiation range and up to 10% at the 1.3–1.55 μn infrared range. The dark counts are below 0.01 per second. The measured real-time counting rate is above 2 GHz and is limited by readout electronics (the intrinsic response time is below 30 ps). The SSPD jitter is below 18 ps, and the best-measured value of the noise-equivalent power (NEP) is 2 × 10−18 W/Hz1/2. at 1.3 μm. In terms of photon-counting efficiency and speed, these NbN SSPDs significantly outperform semiconductor avalanche photodiodes and photomultipliers.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0950-0340	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1488
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	Author	Sobolewski, R.; Verevkin, A.; Gol’tsman, G. N.
	Title	Superconducting optical single-photon detectors			Type	Conference Article
	Year	2004	Publication	CLEO/QELS	Abbreviated Journal	CLEO/QELS
	Volume		Issue		Pages	IThD1
	Keywords	SSPD, QE, jitter, dark counts
	Abstract	We review the development of superconducting single-photon detectors. The devices are characterized by experimental quantum efficiency of ~8% for infrared photons, counting rate ~2 GHz, 18 ps jitter, and <0.01 per second dark counts.
	Address
	Corporate Author				Thesis
	Publisher	Optical Society of America	Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number	Sobolewski:04			Serial	1489
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	Author	Cherednichenko, S.; Khosropanah, P.; Berg, T.; Merkel, H.; Kollberg, E.; Drakinskiy, V.; Voronov, B.; Gol’tsman, G.
	Title	Optimization of HEB mixer for the Herschel Space Observatory			Type	Abstract
	Year	2004	Publication	Proc. 15^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 15^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	16
	Keywords	NbN HEB mixers, applications
	Abstract	A mixer development for the HIFI instrument of the Herschel Space Observatory has come to the final stage. In our paper and conference presentation we will describe the most important details of the Band 6 Low and High Mixer Unit design. Special attention will be given to the optimization of the hot- electron bolometer mixer chip, which is based on 3.5nm NbN superconducting film on silicon. As the HEB’s local oscillator power requirements depend on the bolometer size, we have compared mixer noise temperature for different bolometer width- to- length ratio. A trade- off between mixer performance and local oscillator power requirements results in the mixer units equipped with optimized mixer chips, providing the largest coverage of the Band6 RF band with the lowest possible receiver noise. A short account of the beam pattern measurements of Band6 mixers will be given as well.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1490
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	Author	Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Baryshev, A.; Kooi, J.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol’tsman, G.
	Title	Hot electron bolometer mixers with improved interfaces: sensitivity, LO power and stability			Type	Conference Article
	Year	2004	Publication	Proc. 15^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 15^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	17-24
	Keywords	NbN HEB mixers
	Abstract	We study twin slot antenna coupled NbN hot electron bolometer mixers with an improved contact structure and a small volume, ranging from 1 µm × 0.1 µm to 2 × 0.3 µm. We obtain a DSB receiver noise temperature of 900 K at 1.6 THz and 940 K at 1.9 THz. To explore the practical usability of such small HEB mixers we evaluate the LO power requirement, the sensitivity and the stability. We find that the LO power requirement of the smallest mixers is reduced to about 240 nW at the Si lens of the mixer. This value is larger than expected from the isothermal technique and the known losses in the lens by a factor of 3-3.5. The stability of these receivers is characterized using a measurement of the Allan Variance. We find an Allan time of 0.5 sec. in an 80 MHz bandwidth. A small increase in stability can be reached by using a higher bias at the expense of a significant amount of sensitivity. The stability is sufficient for spectroscopic applications in a 1 MHz bandwidth at a 1 Hz chopping frequency.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1491
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	Author	Semenov, Alexei D.; Hübers, Heinz-Wilhelm; Richter, Heiko; Smirnov, Konstantin; Gol'tsman, Gregory N.; Voronov, Boris M.
	Title	Superconducting hot-electron bolometer mixer for terahertz heterodyne receivers			Type	Abstract
	Year	2004	Publication	Proc. 15^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 15^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	164
	Keywords	NbN HEB mixers
	Abstract	A number of on-going astronomical and atmospheric research programs are aimed to the Terahertz (THz) spectral region. At frequencies above about 1.4 THz heterodyne receivers planned for these missions will use superconducting hot-electron bolometers as a mixers. We present current results on the development of superconducting NbN hot- electron bolometer mixer and quasioptical radiation coupling scheme for GREAT (German Receiver for Astronomy at Terahertz Frequencies, to be used aboard of SOFIA) and TELIS (Terahertz Limb Sounder). The mixer is incorporated into hybrid antenna consisting of a planar feed antenna, which has either logarithmic spiral or double-slot configuration, and hyperhemispherical silicon lens. For the log-spiral feed antenna, the double side-band receiver noise temperature of 5500 K was achieved at 4.3 THz. The noise temperature shows less than 3 dB increase in the intermediate frequency band from 4 GHz to 7 GHz. The hybrid antenna had almost frequency independent and symmetric radiation pattern with the beam-width slightly broader than expected for a diffraction limited pattern. Results of FTS measurements in the direct detection regime agreed with the spectral dependence of the noise temperature for spiral antennas with different spacing of inner terminals.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1492
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	Author	Ryabchun, S.; Korneev, A.; Matvienko, V.; Smirnov, K.; Kouminov, P.; Seleznev, V.; Kaurova, N.; Voronov, B.; Gol’tsman, G. N.
	Title	Superconducting single photon detectors array based on hot electron phenomena			Type	Conference Article
	Year	2004	Publication	Proc. 15^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 15^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	242-247
	Keywords	NbN SSPD arrays, SNSPD
	Abstract	In this paper we propose to use time domain multiplexing for large format arrays of superconducting single photon detectors (SSPDs) of the terahertz, visible and infrared frequency ranges based on ultrathin superconducting NbN films. Effective realization of time domain multiplexing for SSPD arrays is possible due to a short electric pulse of the SSPD as response to radiation quantum absorption, picosecond jitter and extremely low noise equivalent power (NEP). We present experimental results of testing 2×2 arrays in the infrared waveband. The measured noise equivalent power in the infrared and expected for the terahertz waveband is 10 – 21 WHz -1/2 . The best quantum efficiency (QE) of SSPD is 50% at 1.3 µm wavelength.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1493
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	Author	Hajenius, M.; Baselmans, J. J. A.; Gao, J. R.; Klapwijk, T. M.; de Korte 2, P. A. J.; Voronov, B.; Gol’tsman, G.
	Title	Increased bandwidth of NbN phonon cooled hot electron bolometer mixers			Type	Conference Article
	Year	2004	Publication	Proc. 15^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 15^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	381-386
	Keywords	NbN HEB mixers, IF bandwidth
	Abstract	We study experimentally the IF gain bandwidth of NbN phonon-cooled hot-electron-bolometer (HEB) mixers for a set of devices with different contact structures but an identical NbN film. We observe that the IF bandwidth depends strongly on the exact contact structure and find an IF gain bandwidth of 6 GHz for a device with an additional superconducting layer (NbTiN) in between the active NbN film and the gold contact to the antenna. These results contradict the common opinion that the IF bandwidth is determined by the phonon-escape time between the NbN film and the substrate. Hence we calculate the IF gain bandwidth of a superconducting film using a two-temperature model. We find that the bandwidth increases strongly with operating temperature and is not limited by the phonon escape time. This is because of strong temperature dependence of the phonon specific heat in the NbN film.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1494
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	Author	Goltsman, G.; Korneev, A.; Izbenko, V.; Smirnov, K.; Kouminov, P.; Voronov, B.; Kaurova, N.; Verevkin, A.; Zhang, J.; Pearlman, A.; Slysz, W.; Sobolewski, R.
	Title	Nano-structured superconducting single-photon detectors			Type	Journal Article
	Year	2004	Publication	Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment	Abbreviated Journal
	Volume	520	Issue	1-3	Pages	527-529
	Keywords	NbN SSPD, SNSPD
	Abstract	NbN detectors, formed into meander-type, 10×10-μm2 area structures, based on ultrathin (down to 3.5-nm thickness) and nanometer-width (down to below 100 nm) NbN films are capable of efficiently detecting and counting single photons from the ultraviolet to near-infrared optical wavelength range. Our best devices exhibit QE >15% in the visible range and ∼10% in the 1.3–1.5-μm infrared telecommunication window. The noise equivalent power (NEP) ranges from ∼10−17 W/Hz1/2 at 1.5 μm radiation to ∼10−19 W/Hz1/2 at 0.56 μm, and the dark counts are over two orders of magnitude lower than in any semiconducting competitors. The intrinsic response time is estimated to be <30 ps. Such ultrafast detector response enables a very high, GHz-rate real-time counting of single photons. Already established applications of NbN photon counters are non-invasive testing and debugging of VLSI Si CMOS circuits and quantum communications.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0168-9002	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1495
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	Author	Gao, J. R.; Hajenius, M.; Baselmans, J. J. A.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol'tsman, G.
	Title	NbN hot electron bolometer mixers with superior performance for space applications			Type	Conference Article
	Year	2004	Publication	Proc. Int. workshop on low temp. electronics	Abbreviated Journal	Proc. Int. workshop on low temp. electronics
	Volume		Issue		Pages	11-17
	Keywords	NbN HEB mixers, applications
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Noordwijk	Editor	Armandillo, E.; Leone, B.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	International workshop on low temperature electronics- WOLTE 6 - Noordwijk
	Notes				Approved	no
	Call Number				Serial	1496
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	Author	Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol'tsman, G.
	Title	Noise performance of NbN hot electron bolometer mixers at 2.5 THz and its dependence on the contact resistance			Type	Conference Article
	Year	2003	Publication	Proc. 14^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 14^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	11-19
	Keywords	NbN HEB mixers
	Abstract	NbN hot electron bolometer mixers (HEBM) are at this moment the best heterodyne receivers for frequencies above 1 Thz. However, the fabrication procedure of these devices is such that the quality of the interface between the NbN superconducting film and the contact structure is not under good control. The result is a low transparency interface between the bolometer itself and the contact/antenna structure. In this paper we report a detailed experimental study on a novel idea to increase the transparency of this interface. This leads to a record sensitivity and more reproducible performance. We compare identical bolometers, coupled with a spiral antenna, with different NbN bolometer-contact pad interfaces. We find that cleaning the NbN interface alone results in an increase in the noise temperature. However, cleaning the NbN interface and adding a thin additional superconductor prior to the gold contact deposition improves the noise temperature of the HEBm with more than a factor of 2. A device with a contact pad on top of an in-situ cleaned NbN film consisting of 10 nm of NbTiN and 40 nm of gold has a DSB noise temperature of 1050 K at 2.5 THz.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1497
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	Author	Semenov, Alexei D.; Hiibers, Heinz-Wilhelm; Richter, Heiko; Smirnov, Konstantin; Gol'tsman, Gregory N.; Kaurova, Natalia; Voronov, Boris M.
	Title	Superconducting hot-electron bolometer mixer for terahertz heterodyne receivers			Type	Conference Article
	Year	2003	Publication	Proc. 14^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 14^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	33-40
	Keywords	NbN HEB mixers
	Abstract	A number of on-going astronomical and atmospheric research programs are aimed to the Terahertz (THz) spectral region. At frequencies above about 1.4 THz heterodyne receivers planned for these missions will use superconducting hot-electron bolometers as a mixers. We present recent results of the terahertz antenna development of superconducting NbN hot-electron bolometer mixer for GREAT (German Receiver for Astronomy at Terahertz Frequencies, to be used aboard of SOFIA) and TELIS (Terahertz Limb Sounder). The mixer is incorporated into hybrid antenna consisting of a planar feed antenna, which has either logarithmic spiral or double-slot configuration, and hyper hemispherical silicon lens. The hybrid antenna showed almost frequency independent and symmetric radiation pattern with the beam-width slightly broader than expected for diffraction limited antenna. The noise temperature as well as its spectral dependence changes with the bolometer sizes that provides additional tool for mixer optimization. FTS spectra measured in the direct detection regime agreed with the noise temperature spectra.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1498
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	Author	Yagoubov, P. L.; Hoogeveen, R. W. M.; Maurellis, A. M.; Mair, U.; Krocka, M.; Wagner, G.; Birk, M.; Hiibers, H.-W.; Richter, H.; Semenov, A.; Gol'tsman, G.; Voronov, B.; Koshelets, V.; Shitov, S.; Ellison, B.; Kerridge, B.; Matheson, D.; Alderman, B.; Harman, M.; Siddans, R.; Reburn, J.
	Title	TELIS — development of a new balloon borne THz/submm heterodyne limb sounder			Type	Conference Article
	Year	2003	Publication	Proc. 14^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 14^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	204-214
	Keywords	limb-sounder, TELIS
	Abstract	We present a design concept for a new state-of-the-art balloon borne atmospheric monitor that will allow enhanced limb sounding of the Earth's atmosphere within the submillimeter and far-infrared wavelength spectral range: TELIS, TErahertz and submm LImb Sounder. The instrument is being developed by a consortium of major European institutes that includes the Space Research Organisation of the Netherlands (SRON), the Rutherford Appleton Laboratory (RAL) in the United Kingdom and the Deutschen Zentrum far Luft- und Raumfahrt (DLR) in Germany (lead institute). TELIS will utilise state-of-the-art superconducting heterodyne technology and is designed to be a compact, lightweight instrument capable of providing broad spectral coverage, high spectral resolution and long flight duration (-24 hours duration during a single flight campaign). The combination of high sensitivity and extensive flight duration will allow evaluation of the diurnal variation of key atmospheric constituents such as OH, HO,, C10, BrO together will longer lived constituents such as 0 3 , HCL and N 2 0. Furthermore, TELIS will share a common balloon platform to that of the MIPAS-B Fourier Transform Spectrometer, developed by the Institute of Meteorology and Climate research of the University of Karlsruhe, Germany. MIPAS-B will provide simultaneous and complementary spectral measurements over an extended spectral range. The combination of the TELIS and MIPAS instruments will provide atmospheric scientists with a very powerful observational tool. TELIS will serve as a testbed for new cryogenic heterodyne detection techniques, and as such it will act as a prelude to future spacebome instruments planned by the European Space Agency (ESA).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1499
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	Author	Tong, C.-Y. Edward; Meledin, Denis; Blundell, Raymond; Erickson, Neal; Kawamura, Jonathan; Mehdi, Imran; Gol'tsman, Gregory
	Title	A 1.5 THz hot-electron bolometer mixer operated by a planar diode-based local oscillator			Type	Abstract
	Year	2003	Publication	Proc. 14^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 14^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	286
	Keywords	waveguide NbN HEB mixers
	Abstract	We describe a 1.5 THz heterodyne receiver based on a superconductin g hot-electron bolometer mixer, which is pumped by an all-solid-state local oscillator chain. The bolometer is fabricated from a 3.5 nm-thick niobium nitride film deposited on a quartz substrate with a 200 nm-thick magnesium oxide buffer layer. The bolometer measures 0.15 fun in width and 1.5 1..tm in length. The chip consisting of the bolometer and mixer circuitry is incorporated in a fixed-tuned waveguide mixer block with a corru g ated feed horn. The local oscillator unit comprises of a cascade of four planar doublers followin g a MMIC-based W-band power amplifier. The local oscillator is coupled to the mixer using a Martin-Puplett interferometer. The local oscillator output power needed for optimal receiver performance is approximately 1 to 2 11W, and the chain is able to provide this power at a number of frequency points between 1.45 and 1.56 THz. By terminating the rf input with room temperature and 77 K loads, a Y-factor of 1.11 (DSB) has been measured at a local oscillator frequency of 1.476 THz at 3 GHz intermediate frequency.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1501
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	Author	Smirnov, K. V.; Vachtomin, Yu. B.; Antipov, S. V.; Maslennikov, S. N.; Kaurova, N. S.; Drakinsky, V. N.; Voronov, B. M.; Gol'tsman, G. N.; Semenov, A. D.; Richter, H.; Hubers, H.-W.
	Title	Noise and gain performance of spiral antenna coupled HEB mixers at 0.7 THz and 2.5 THz			Type	Conference Article
	Year	2003	Publication	Proc. 14^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 14^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	405-412
	Keywords	NbN HEB mixers
	Abstract	Noise and gain performance of hot electron bolometer (HEB) mixers based on ultrathin superconducting NbN films integrated with a spiral antenna was studied. The noise temperature measurements for two samples with different active area of 3 p.m x 0.24 .tni and 1.3 1..tm x 0.12 1.tm were performed at frequencies 0.7 THz and 2.5 THz. The best receiver noise temperatures 370 K and 1600 K, respectively, have been found at these frequencies. The influence of contact resistance between the superconductor and the antenna terminals on the noise temperature of HEB is discussed. The noise and gain bandwidth of 5GHz and 4.2 GHz, respectively, are demonstrated for similar HEB mixer at 0.75 THz.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1502
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	Author	Il'in, K.; Siegel, M.; Semenov, A.; Engel, A.; Hübers, H.-W.; Hollmann, E.; Gol'tsman, G.; Voronov, B.
	Title	Thickness dependence of superconducting properties of ultrathin Nb and NbN films			Type	Conference Article
	Year	2004	Publication	AKF-Frühjahrstagung	Abbreviated Journal
	Volume		Issue		Pages
	Keywords	Nb, NbN films, has potential plagiarism
	Abstract
	Address	Berlin-Adlershof
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1503
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	Author	Semenov, A.; Richter, H.; Hübers, H.-W.; Smirnov, K.; Voronov, B.; Gol'tsman, G.
	Title	Development of terahertz superconducting hot-electron bolometer mixers			Type	Conference Article
	Year	2003	Publication	Proc. 6th European Conf. Appl. Supercond.	Abbreviated Journal	Proc. 6th European Conf. Appl. Supercond.
	Volume	181	Issue		Pages	2960-2965
	Keywords	NbN HEB mixers
	Abstract	We present recent results of the development of phonon cooled hot-electron bolometric (HEB) mixers for airborne and balloon borne terahertz heterodyne receivers. Three iomportant issues have been addresses: the quality of NbN films the HEB mixers were made from, the spectral properties of the HEB mixers and the local oscillator power required for optical operation. Studies with an atomic force microscope indicate, that the performance of the HEB mixer might have been effected by the microstructure of the NbN film. Antenna gain and noise temperature were investigated at terahertz frequencies for a HEB embedded in either log-spiral or twin-slot feed antenna. Comparison suggests that at frequencies above 3 THz the spiral feed provides better overall performance. At 1.6 THz, a power of 2.5 µW was required from the local oscillator for optimal operation of the HEB mixer.
	Address	Sorrento, Italy
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN	0750309814, 978-0750309813	Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1505
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	Author	Richter, H.; Semenov, A.; Hubers, H.-W.; Smirnov, K.; Gol’tsman, G.; Voronov, B.
	Title	Phonon cooled hot-electron bolometric mixer for 1-5 THz			Type	Conference Article
	Year	2004	Publication	Proc. 29th IRMMW / 12th THz	Abbreviated Journal	Proc. 29th IRMMW / 12th THz
	Volume		Issue		Pages	241-242
	Keywords	NbN HEB mixers
	Abstract	Heterodyne receivers for applications in astronomy and planetary research need quantum limited sensitivity. In instruments which are currently built for SOFIA and Herschel, superconducting hot electron bolometers (HEB) are used to achieve this goal at frequencies above 1.4 THz. In order to optimize the performance for this frequency of hot electron bolometer mixers with different in-plane dimensions and logarithmic-spiral feed antennas have been investigated. Their noise temperatures and beam patterns were measured. Above 3 THz the best performance was achieved with a superconducting bridge of 2.0/spl times/0.2 /spl mu/m/sup 2/ incorporated in a logarithmic spiral antenna. The DSB noise temperatures were 2700 K, 4700 and 6400 K at 3.1 THz, 4.3 THz and 5.2 THz, respectively. The results demonstrate that the NbN HEB is very well suited as a mixer for THz heterodyne receivers up to at least 5 THz.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1506
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	Author	Rubtsova, I.; Korneev, A.; Matvienko, V.; Chulkova, G.; Milostnaya, I.; Goltsman, G.; Pearlman, A.; Slysz, W.; Verevkin, A.; Sobolewski, R.
	Title	Spectral sensitivity, quantum efficiency, and noise equivalent power of NbN superconducting single-photon detectors in the IR range			Type	Conference Article
	Year	2004	Publication	Proc. 29th IRMMW / 12th THz	Abbreviated Journal	Proc. 29th IRMMW / 12th THz
	Volume		Issue		Pages	461-462
	Keywords	NbN SSPD, SNSPD
	Abstract	We have developed nanostructured NbN superconducting single-photon detectors capable of GHz-rate photon counting in the 0.4 to 5 /spl mu/m wavelength range. Quantum efficiency of 30%, dark count rate 3/spl times/10/sup -4/ s/sup -1/, and NEP=10/sup -20/ W/Hz/sup -1/2/ have been measured at the 1.3-/spl mu/m wavelength for the device operating at 2.0 K.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1507
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	Author	Hoogeveen, R. W. M.; Yagoubov, P. A.; Maurellis, A.; Koshelets, V. P.; Shitov, S. V.; Mair, U.; Krocka, M.; Wagner, G.; Birk, M.; Huebers, H.-W.; Richter, H.; Semenov, A.; Gol’tsman, G. N.; Voronov, B. M.; Ellison, B.N.; Kerridge, B.J.; Matheson, D. N.; Alderman, B.; Harman, M.; Siddans, R.; Reburn, J.
	Title	New cryogenic heterodyne techniques applied in TELIS: the balloonborne THz and submillimeter limb sounder for atmospheric research			Type	Conference Article
	Year	2003	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	5152	Issue		Pages	347-355
	Keywords	TELIS, limb sounder, heterodyne detection, terahertz, sub millimeter, cryogenic, limb sounding, balloon borne, atmospheric research
	Abstract	We present a design concept for a new state-of-the-art balloon borne atmospheric monitor that will allow enhanced limb sounding of the Earth’s atmosphere within the submillimeter and far-infrared wavelength spectral range: TELIS, TErahertz and submm LImb Sounder. The instrument is being developed by a consortium of major European institutes that includes the Space Research Organization of the Netherlands (SRON), the Rutherford Appleton Laboratory (RAL) will utilize state-of-the-art superconducting heterodyne technology and is designed to be a compact, lightweight instrument cpaable of providing broad spectral coverage, high spectral resolution and long flight duration ( 24 hours duration during a single flight campaign). The combination of high sensitivity and extensive flight duration will allow evaluation of the diurnal variation of key atmospheric constitutenets sucyh as OH, HO2, ClO, BrO togehter will onger lived constituents such as O₃, HCL and N₂O. Furthermore, TELIS will share a common balloon platform to that of the MIPAS-B Fourier Transform Spectrometer, developed by the Institute of Meteorology and Climate research of the over an extended spectral range. The combination of the TELIS and MIPAS instruments will provide atmospheric scientists with a very powerful observational tool. TELIS will serve as a testbed for new cryogenic heterodyne detection techniques, and as such it will act as a prelude to future spaceborne instruments planned by the European Space Agency (ESA).
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Strojnik, M.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Infrared Spaceborne Remote Sensing XI
	Notes				Approved	no
	Call Number				Serial	1508
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	Author	Meledin, D.; Tong, C.-Y. E.; Blundell, R.; Goltsman, G.
	Title	Measurement of intermediate frequency bandwidth of hot electron bolometer mixers at terahertz frequency range			Type	Journal Article
	Year	2003	Publication	IEEE Microw. Wireless Compon. Lett.	Abbreviated Journal	IEEE Microw. Wireless Compon. Lett.
	Volume	13	Issue	11	Pages	493-495
	Keywords	waveguide NbN HEB mixers
	Abstract	We have developed a new experimental setup for measuring the IF bandwidth of superconducting hot electron bolometer mixers. In our measurement system we use a chopped hot filament as a broadband signal source, and can perform a high-speed IF scan with no loss of accuracy when compared to coherent methods. Using this technique we have measured the 3 dB IF bandwidth of hot electron bolometer mixers, designed for THz frequency operation, and made from 3-4 nm thick NbN film deposited on an MgO buffer layer over crystalline quartz.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1531-1309	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1509
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	Author	Zhang, J.; Pearlman, A.; Slysz, W.; Verevkin, A.; Sobolewski, R.; Wilsher, K.; Lo, W.; Okunev, O.; Korneev, A.; Kouminov, P.; Chulkova, G.; Gol’tsman, G. N.
	Title	A superconducting single-photon detector for CMOS IC probing			Type	Conference Article
	Year	2003	Publication	Proc. 16-th LEOS	Abbreviated Journal	Proc. 16-th LEOS
	Volume	2	Issue		Pages	602-603
	Keywords	NbN SSPD, SNSPD
	Abstract	In this paper, a novel, time-resolved, NbN-based, superconducting single-photon detector (SSPD) has been developed for probing CMOS integrated circuits (ICs) using photon emission timing analysis (PETA).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	The 16th Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2003. LEOS 2003.
	Notes				Approved	no
	Call Number				Serial	1510
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	Author	Korneev, A.; Lipatov, A.; Okunev, O.; Chulkova, G.; Smirnov, K.; Gol’tsman, G.; Zhang, J.; Slysz, W.; Verevkin, A.; Sobolewski, R.
	Title	GHz counting rate NbN single-photon detector for IR diagnostics of VLSI CMOS circuits			Type	Journal Article
	Year	2003	Publication	Microelectronic Engineering	Abbreviated Journal	Microelectronic Engineering
	Volume	69	Issue	2-4	Pages	274-278
	Keywords	NbN SSPD, SNSPD, applications
	Abstract	We present a new, simple to manufacture superconducting single-photon detector operational in the range from ultraviolet to mid-infrared radiation wavelengths. The detector combines GHz counting rate, high quantum efficiency and very low level of dark (false) counts. At 1.3–1.5 μm wavelength range our detector exhibits a quantum efficiency of 5–10%. The detector photoresponse voltage pulse duration was measured to be about 150 ps with jitter of 35 ps and both of them were limited mostly by our measurement equipment. In terms of quantum efficiency, dark counts level, speed of operation the detector surpasses all semiconductor counterparts and was successfully applied for CMOS integrated circuits diagnostics.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0167-9317	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1511
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	Author	Zhang, J.; Boiadjieva, N.; Chulkova, G.; Deslandes, H.; Gol'tsman, G. N.; Korneev, A.; Kouminov, P.; Leibowitz, M.; Lo, W.; Malinsky, R.; Okunev, O.; Pearlman, A.; Slysz, W.; Smirnov, K.; Tsao, C.; Verevkin, A.; Voronov, B.; Wilsher, K.; Sobolewski, R.
	Title	Noninvasive CMOS circuit testing with NbN superconducting single-photon detectors			Type	Journal Article
	Year	2003	Publication	Electron. Lett.	Abbreviated Journal	Electron. Lett.
	Volume	39	Issue	14	Pages	1086-1088
	Keywords	NbN SSPD, SNSPD, applications
	Abstract	The 3.5 nm thick-film, meander-structured NbN superconducting single-photon detectors have been implemented in the CMOS circuit-testing system based on the detection of near-infrared photon emission from switching transistors and have significantly improved the performance of the system. Photon emissions from both p- and n-MOS transistors have been observed.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0013-5194	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1512
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	Author	Sobolewski, R.; Zhang, J.; Slysz, W.; Pearlman, A.; Verevkin, A.; Lipatov, A.; Okunev, O.; Chulkova, G.; Korneev, A.; Smirnov, K.; Kouminov, P.; Voronov, B.; Kaurova, N.; Drakinsky, V.; Goltsman, G. N.
	Title	Ultrafast superconducting single-photon optical detectors			Type	Conference Article
	Year	2003	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	5123	Issue		Pages	1-11
	Keywords	NbN SSPD, SNSPD
	Abstract	We present a new class of single-photon devices for counting of both visible and infrared photons. Our superconducting single-photon detectors (SSPDs) are characterized by the intrinsic quantum efficiency (QE) reaching up to 100%, above 10 GHz counting rate, and negligible dark counts. The detection mechanism is based on the photon-induced hotspot formation and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-wide superconducting stripe. The devices are fabricated from 3.5-nm-thick NbN films and operate at 4.2 K, well below the NbN superconducting transition temperature. Various continuous and pulsed laser sources in the wavelength range from 0.4 Î¼m up to >3 Î¼m were implemented in our experiments, enabling us to determine the detector QE in the photon-counting mode, response time, and jitter. For our best 3.5-nm-thick, 10Ã—10 Î¼m²-area devices, QE was found to reach almost 100% for any wavelength shorter than about 800 nm. For longer-wavelength (infrared) radiation, QE decreased exponentially with the photon wavelength increase. Time-resolved measurements of our SSPDs showed that the system-limited detector response pulse width was below 150 ps. The system jitter was measured to be 35 ps. In terms of the counting rate, jitter, and dark counts, the NbN SSPDs significantly outperform their semiconductor counterparts. Already identifeid and implemented applications of our devices range from noninvasive testing of semiconductor VLSI circuits to free-space quantum communications and quantum cryptography.
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Spigulis, J.; Teteris, J.; Ozolinsh, M.; Lusis, A.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Advanced Optical Devices, Technologies, and Medical Applications
	Notes				Approved	no
	Call Number				Serial	1513
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	Author	Verevkin, A. A.; Pearlman, A.; Slysz, W.; Zhang, J.; Sobolewski, R.; Chulkova, G.; Okunev, O.; Kouminov, P.; Drakinskij, V.; Smirnov, K.; Kaurova, N.; Voronov, B.; Gol’tsman, G.; Currie, M.
	Title	Ultrafast superconducting single-photon detectors for infrared wavelength quantum communications			Type	Conference Article
	Year	2003	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	5105	Issue		Pages	160-170
	Keywords	NbN SSPD, SNSPD, applications, single-photon detector, quantum cryptography, quantum communications, superconducting devices
	Abstract	We have developed a new class of superconducting single-photon detectors (SSPDs) for ultrafast counting of infrared (IR) photons for secure quantum communications. The devices are operated on the quantum detection mechanism, based on the photon-induced hotspot formation and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-wide superconducting stripe. The detectors are fabricated from 3.5-nm-thick NbN films and they operate at 4.2 K inside a closed-cycle refrigerator or liquid helium cryostat. Various continuous and pulsed laser sources have been used in our experiments, enabling us to determine the detector experimental quantum efficiency (QE) in the photon-counting mode, response time, time jitter, and dark counts. Our 3.5-nm-thick SSPDs reached QE above 15% for visible light photons and 5% at 1.3 – 1.5 Î¼m infrared range. The measured real-time counting rate was above 2 GHz and was limited by the read-out electronics (intrinsic response time is <30 ps). The measured jitter was <18 ps, and the dark counting rate was <0.01 per second. The measured noise equivalent power (NEP) is 2 x 10^-18 W/Hz^1/2 at Î» = 1.3 Î¼m. In near-infrared range, in terms of the counting rate, jitter, dark counts, and overall sensitivity, the NbN SSPDs significantly outperform their semiconductor counterparts. An ultrafast quantum cryptography communication technology based on SSPDs is proposed and discussed.
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Donkor, E.; Pirich, A.R.; Brandt, H.E.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Quantum Information and Computation
	Notes				Approved	no
	Call Number				Serial	1514
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	Author	Gol’tsman, G. N.; Smirnov, K.; Kouminov, P.; Voronov, B.; Kaurova, N.; Drakinsky, V.; Zhang, J.; Verevkin, A.; Sobolewski, R.
	Title	Fabrication of nanostructured superconducting single-photon detectors			Type	Journal Article
	Year	2003	Publication	IEEE Trans. Appl. Supercond.	Abbreviated Journal	IEEE Trans. Appl. Supercond.
	Volume	13	Issue	2	Pages	192-195
	Keywords	NbN SSPD, SNSPD
	Abstract	Fabrication of NbN superconducting single-photon detectors, based on the hotspot effect is presented. The hotspot formation arises in an ultrathin and submicrometer-width superconductor stripe and, together with the supercurrent redistribution, leads to the resistive detector response upon absorption of a photon. The detector has a meander structure to maximally increase its active area and reach the highest detection efficiency. Main processing steps, leading to efficient devices, sensitive in 0.4-5 /spl mu/m wavelength range, are presented. The impact of various processing steps on the performance and operational parameters of our detectors is discussed.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1558-2515	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1515
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	Author	Zhang, J.; Pearlman, A.; Slysz, W.; Verevkin, A.; Sobolewski, R.; Okunev, O.; Korneev, A.; Kouminov, P.; Smirnov, K.; Chulkova, G.; Gol’tsman, G. N.; Lo, W.; Wilsher, K.
	Title	Infrared picosecond superconducting single-photon detectors for CMOS circuit testing			Type	Conference Article
	Year	2003	Publication	CLEO/QELS	Abbreviated Journal	CLEO/QELS
	Volume		Issue		Pages	Cmv4
	Keywords	NbN SSPD; SNSPD; Infrared; Quantum detectors; Electron beam lithography; Infrared detectors; Infrared radiation; Quantum efficiency; Single photon detectors; Superconductors
	Abstract	Novel, NbN superconducting single-photon detectors have been developed for ultrafast, high quantum efficiency detection of single quanta of infrared radiation. Our devices have been successfully implemented in a commercial VLSI CMOS circuit testing system.
	Address
	Corporate Author				Thesis
	Publisher	Optical Society of America	Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference
	Notes				Approved	no
	Call Number				Serial	1518
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	Author	Zhang, J.; Słysz, W.; Pearlman, A.; Verevkin, A.; Sobolewski, R.; Okunev, O.; Chulkova, G.; Gol’tsman, G. N.
	Title	Time delay of resistive-state formation in superconducting stripes excited by single optical photons			Type	Journal Article
	Year	2003	Publication	Phys. Rev. B	Abbreviated Journal	Phys. Rev. B
	Volume	67	Issue	13	Pages	132508 (1 to 4)
	Keywords	NbN SSPD, SNSPD
	Abstract	We have observed a 65(±5)-ps time delay in the onset of a resistive-state formation in 10-nm-thick, 130-nm-wide NbN superconducting stripes exposed to single photons. The delay in the photoresponse decreased to zero when the stripe was irradiated by multi-photon (classical) optical pulses. Our NbN structures were kept at 4.2 K, well below the material’s critical temperature, and were illuminated by 100-fs-wide optical pulses. The time-delay phenomenon has been explained within the framework of a model based on photon-induced generation of a hotspot in the superconducting stripe and subsequent, supercurrent-assisted, resistive-state formation across the entire stripe cross section. The measured time delays in both the single-photon and two-photon detection regimes agree well with theoretical predictions of the resistive-state dynamics in one-dimensional superconducting stripes.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0163-1829	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1519
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	Author	Baubert, J.; Salez, M.; Delorme, Y.; Pons, P.; Goltsman, G.; Merkel, H.; Leconte, B.
	Title	Membrane-based HEB mixer for THz applications			Type	Conference Article
	Year	2003	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	5116	Issue		Pages	551-562
	Keywords	membrane NbN HEB mixers, heterodyne receiver, stress-less membrane, coupling efficiency, submillimeter-waves frequency, low-cost space applications
	Abstract	We report in this paper a new concept for 2.7 THz superconducting Niobium nitride (NbN) Hot-Electron Bolometer mixer (HEB). The membrane process was developped for space telecommnunication applications a few years ago and the HEB mixer concept is now considered as the best choice for low-noise submillimeter-wave frequency heterodyne receivers. The idea is then to join these two technologies. The novel fabrication scheme is to fabricate a NbN HEB mixer on a 1 μm thick stress-less Si₃N₄/SiO₂ membrane. This seems to present numerous improvements concerning : use at higher RF frequencies, power coupling efficiency, HEB mixer sensitivity, noise temperature, and space applications. This work is to be continued within the framework of an ESA TRP project, a 2.7 THz heterodyne camera with numerous applications including a SOFIA airborne receiver. This paper presents the whole fabrication process, the validation tests and preliminary results. Membrane-based HEB mixer theory is currently being investigated and further tests such as heterodyne and Fourier transform spectrometry measurement are planed shortly.
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Chiao, J.-C.; Varadan, V.K.; Cané, C.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Smart Sensors, Actuators, and MEMS
	Notes				Approved	no
	Call Number				Serial	1520
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	Author	Cherednichenko, S.; Khosropanah, P.; Adam, A.; Merkel, H. F.; Kollberg, E. L.; Loudkov, D.; Gol'tsman, G. N.; Voronov, B. M.; Richter, H.; Huebers, H.-W.
	Title	1.4- to 1.7-THz NbN hot-electron bolometer mixer for the Herschel space observatory			Type	Conference Article
	Year	2003	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	4855	Issue		Pages	361-370
	Keywords	NbN HEB mixers
	Abstract	NbN hot- electron bolometer mixers have reached the level of 10hv/k in terms of the input noise temperature with the noise bandwidth of 4-6 GHz from subMM band up to 2.5 THz. In this paper we discuss the major characteristics of this kind of receiver, i.e. the gain and the noise bandwidth, the noise temperature in a wide RF band, bias regimes and optimisation of RF coupling to the quasioptical mixer. We present the status of the development of the mixer for Band 6 Low for Herschel Telescope.
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Phillips, T.G.; Zmuidzinas, J.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Millimeter and Submillimeter Detectors for Astronomy
	Notes				Approved	no
	Call Number				Serial	1521
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	Author	Vakhtomin, Y. B.; Finkel, M. I.; Antipov, S. V.; Smirnov, K. V.; Kaurova, N. S.; Drakinskii, V. N.; Voronov, B. M.; Gol’tsman, G. N.
	Title	The gain bandwidth of mixers based on the electron heating effect in an ultrathin NbN film on a Si substrate with a buffer MgO layer			Type	Journal Article
	Year	2003	Publication	J. of communications technol. & electronics	Abbreviated Journal	J. of communications technol. & electronics
	Volume	48	Issue	6	Pages	671-675
	Keywords	NbN HEB mixers
	Abstract	Measurements of the intermediate frequency band 900 GHz of mixers based on the electron heating effect (EHE) in 2-nm- and 3.5-nm-thick superconducting NbN films sputtered on MgO and Si substrates with buffer MgO layers are presented. A 2-nm-thick superconducting NbN film with a critical temperature of 9.2 K has been obtained for the first time using a buffer MgO layer.
	Address
	Corporate Author				Thesis
	Publisher	MAIK Nauka/Interperiodica, Birmingham, AL	Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1064-2269	ISBN		Medium
	Area		Expedition		Conference
	Notes	https://elibrary.ru/item.asp?id=17302119 (Полоса преобразования смесителей на эффекте разогрева электронов в ультратонких пленках NbN на подложках из Si с подслоем MgO)			Approved	no
	Call Number	Vakhtomin2003			Serial	1522
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	Author	Verevkin, A. A.; Zhang, J.; Slysz, W.; Sobolewski, R.; Lipatov, A. P.; Okunev, O.; Chulkova, G.; Korneev, A.; Gol’tsman, G. N.
	Title	Superconducting single-photon detectors for GHz-rate free-space quantum communications			Type	Conference Article
	Year	2002	Publication	Proc. SPIE	Abbreviated Journal	Proc. SPIE
	Volume	4821	Issue		Pages	447-454
	Keywords	NbN SSPD, SNSPD, single-photon detector, thin-film superconductivity, quantum cryptography, ultrafast communications
	Abstract	We report our studies on the performance of new NbN ultrathin-film superconducting single-photon detectors (SSPDs). Our SSPDs exhibit experimentally measured quantum efficiencies from 5% at wavelength λ = 1550 nm up to 10% at λ = 405 nm, with exponential, activation-energy-type spectral sensitivity dependence in the 0.4-μm – 3-μm wavelength range. Using a variable optical delay setup, we have shown that our NbN SSPDs can resolve optical photons with a counting rate up to 10 GHz, presently limited by the read-out electronics. The measured device jitter was below 35 ps under optimum biasing conditions. The extremely high photon counting rate, together with relatively high (especially for λ > 1 μm) quantum efficiency, low jitter, and very low dark counts, make NbN SSPDs very promising for free-space communications and quantum cryptography.
	Address
	Corporate Author				Thesis
	Publisher	SPIE	Place of Publication		Editor	Ricklin, J.C.; Voelz, D.G.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Free-Space Laser Communication and Laser Imaging II
	Notes				Approved	no
	Call Number				Serial	1523
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	Author	Hübers, Heinz-Wilhelm; Semenov, A.; Richter, H.; Smirnov, K.; Gol'tsman, G.; Voronov, B.
	Title	Phonon cooled far-infrared hot electron bolometer mixer			Type	Abstract
	Year	2002	Publication	NASA/ADS	Abbreviated Journal	NASA/ADS
	Volume		Issue		Pages
	Keywords	NbN HEB mixers
	Abstract	Heterodyne receivers for applications in astronomy need quantum-limited sensitivity. At frequencies above 1.4 THz superconducting hot electron bolometers (HEB) can be used to achieve this goal. We present results of the development of a quasi-optical phonon-cooled NbN HEB mixer for GREAT, the German heterodyne receiver for SOFIA. Different mixers with logarithmic spiral and double slot feed antennas have been investigated with respect to their noise temperature, conversion loss, linearity and beam pattern at several frequencies between 0.7 THz and 5.2 THz. At 2.5 THz a double sideband noise temperature of 2200 K was achieved. The conversion loss was 16 dB. The response of the mixer was linear up to 400 K load temperature. This performance was verified by measuring an emission line of methanol at 2.5 THz. The results demonstrate that the NbN HEB is very well suited as a mixer for FIR heterodyne receivers.
	Address	Monterey, CA
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference	Far-IR, Sub-mm & MM Detector Technology Workshop, 1-3 April 2002
	Notes	id.37			Approved	no
	Call Number				Serial	1534
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