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	Author	Gershenzon, E. M.; Gol'tsman, G. N.; Semenov, A. D.; Sergeev, A. V.
	Title	Heating of electrons in resistive state of superconducting films. Detectors, mixers and switches			Type	Conference Article
	Year	1992	Publication	Progress in High Temperature Superconductivity	Abbreviated Journal	Progress in High Temperature Superconductivity
	Volume	32	Issue		Pages	190-195
	Keywords	superconducting films, heating of electrons
	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	International Conference on High Temperature Superconductivity and Localization Phenomena , Moscow, Russia , 11 – 15 May 1991
	Notes	https://books.google.co.kr/books?hl=en&lr=&id=uCI0DwAAQBAJ&oi=fnd&pg=PA190&ots=z7WGjXYWr4&sig=TQ6G6dKsmcj4faYe1ZLw_BFmps8			Approved	no
	Call Number				Serial	1666
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	Author	Kroug, M.; Yagoubov, P.; Gol'tsman, G.; Kollberg, E.
	Title	NbN quasioptical phonon cooled hot electron bolometric mixers at THz frequencies			Type	Conference Article
	Year	1997	Publication	Inst. Phys. Conf. Ser.	Abbreviated Journal	Inst. Phys. Conf. Ser.
	Volume	1	Issue		Pages	405-408
	Keywords	NbN HEB mixers
	Abstract
	Address	Veldhoven
	Corporate Author				Thesis
	Publisher		Place of Publication	Bristol	Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0951-3248	ISBN		Medium
	Area		Expedition		Conference	3rd Eur. Conf. on Applied Superconductivity
	Notes				Approved	no
	Call Number				Serial	1600
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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	Gershenzon, E. M.; Gol'tsman, G. N.; Kagane, M. L.
	Title	Observation of free carrier resonances in p-type germanium at submillimeter wavelengths			Type	Journal Article
	Year	1978	Publication	Sov. Phys. Solid State	Abbreviated Journal	Sov. Phys. Solid State
	Volume	20	Issue	4	Pages	573-579
	Keywords	p-Ge, free carriers, resonances
	Abstract	The spectrum of hole resonances in pure p-Ge for submillimetre in quantizing magnetic fields has been studied and identified. Measurements of photoconductivity spectra of p-Ge were made in the wave range lambda = 2-0.3 mm at temp. of 4.2-15 deg K in magnetic fields H up to 40 Measurements at various frequencies showed that the position of a series of characteristic resonances depends on the frequency of the illumination. This is in line with theoretical conclusions about the effective mass of the carriers increasing with rise in the magnetic field as a result of the interaction of the edge of the valency band with the split spin-orbital interaction of the sub 7 exp + band and the conduction band. The relative intensity of the quantum resonance lines of the free holes depends on the excitation conditions.
	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	1721
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	Author	Hübers, H.-W.; Semenov, A.; Richter, H.; Birk, Manfred; Krocka, Michael; Mair, Ulrich; Smirnov, K.; Gol'tsman, G.; Voronov, B.
	Title	Terahertz heterodyne receiver with a hot-electron bolometer mixer			Type	Conference Article
	Year	2002	Publication	Proc. Far-IR, Sub-mm, and mm Detector Technology Workshop	Abbreviated Journal	Proc. Far-IR, Sub-mm, and mm Detector Technology Workshop
	Volume		Issue		Pages
	Keywords	NbN HEB mixers
	Abstract	During the past decade major advances have been made regarding low noise mixers for terahertz (THz) heterodyne receivers. State of the art hot-electron-bolometer (HEB) mixers have noise temperatures close to the quantum limit and require less than a µW power from the local oscillator (LO). The technology is now at a point where the performance of a practical receiver employing such mixer, rather than the figures of merit of the mixer itself, are of major concern. We have incorporated a phonon-cooled NbN HEB mixer in a 2.5 THz heterodyne receiver and investigated the performance of the receiver. This yields important information for the development of heterodyne receivers such as GREAT (German receiver for astronomy at THz frequencies aboard SOFIA)[1] and TELIS (Terahertz limb sounder), a balloon borne heterodyne receiver for atmospheric research [2]. Both are currently under development at DLR.
	Address	Monterey, CA, USA
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor	Wold, J.; Davidson, J.
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes	4 pages; Unconfirmed but cited in https://kups.ub.uni-koeln.de/1622/1/bedorf.pdf; There is a Program of the Workshop: https://www.yumpu.com/en/document/view/7411055/far-ir-submm-mm-detector-technology-workshop-sofia-usra (there is no title of this article in the Program); There is also identical publication in Proc. ISSTT (Serial: 332, “A broadband terahertz heterodyne receiver with an NbN HEB mixer”).			Approved	no
	Call Number				Serial	1829
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	Author	Verevkin, A.; Zhang, J.; Pearlman, A.; Slysz, W.; Sobolewski, Roman; Korneev, A.; Kouminov, P.; Okunev, O.; Chulkova, G.; Gol'tsman, G.
	Title	Ultimate sensitivity of superconducting single-photon detectors in the visible to infrared range			Type	Miscellaneous
	Year	2004	Publication	ResearchGate	Abbreviated Journal	ResearchGate
	Volume		Issue		Pages
	Keywords	NbN SSPD, SNSPD
	Abstract	We present our quantum efficiency (QE) and noise equivalent power (NEP) measurements of the meandertype ultrathin NbN superconducting single-photon detector in the visible to infrared radiation range. The nanostructured devices with 3.5-nm film thickness demonstrate QE up to~ 10% at 1.3–1.55 µm wavelength, and up to 20% in the entire visible range. The detectors are sensitive to infrared radiation with the wavelengths down to~ 10 µm. NEP of about 2× 10-18 W/Hz1/2 was obtained at 1.3 µm wavelength. Such high sensitivity together with GHz-range counting speed, make NbN photon counters very promising for efficient, ultrafast quantum communications and another applications. We discuss the origin of dark counts in our devices and their ultimate sensitivity in terms of the resistive fluctuations in our superconducting nanostructured devices.
	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	Not attributed to any publisher! File name: PR9VervekinSfin_f.doc; Author: JAOLEARY; Last modification date: 2004-02-26			Approved	no
	Call Number				Serial	1751
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	Author	Gershenzon, E. M.; Gol'tsman, G. N.; Mirskii, G. I.
	Title	Submillimeter backward-wave-tube spectrometer-relaxometer			Type	Journal Article
	Year	1987	Publication	Pribory i Tekhnika Eksperimenta	Abbreviated Journal	Pribory i Tekhnika Eksperimenta
	Volume	30	Issue	4	Pages	131-137
	Keywords	BWO, applications
	Abstract	A backward-wave-tube (BWT) spectrometer-relaxometer is described that is designed for study of the relaxation characteristics of photoconductors in the wavelength range of 2-0.25 mm – in particular, to measure the relaxation times of the submillimeter photoconductivity of germanium in the range of 10[sup:-4]-10[sup:-9] sec and to determine from these data the concentration of compensating impurities of from 10[sup:10] to 10[sup:14] cm[sup:-3]. The instrument uses the beats of the oscillations of two BWTs and records the amplitude-frequency response of the specimen with variation of the beat frequency from 10[sup:4] to 10[sup:8] Hz with accumulation of the desired signal for less than or equal to1 sec by means of a quadrature synchronous detector. The beat frequency is stabilized and the quadrature voltages of the synchronous detector are formed by means of phase-locked loops.
	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	1699
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	Author	Krause, S.; Mityashkin, V.; Antipov, S.; Gol'tsman, G.; Meledin, D.; Desmaris, V.; Belitsky, V.; Rudzinski, M.
	Title	Study of IF bandwidth of NbN hot electron bolometers on GaN buffer layer using a direct measurement method			Type	Conference Article
	Year	2016	Publication	Proc. 27^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal
	Volume		Issue		Pages	30-32
	Keywords	NbN HEB, GaN buffer layer
	Abstract	In this paper, we present a reliable measurement method to study the influence of the GaN buffer layer on phonon-escape time in comparison with commonly used Si substrates and, in consequence, on the IF bandwidth of HEBs. One of the key aspects is to operate the HEB mixer at elevated bath temperatures close to the critical temperature of the NbN ultra-thin film, where contributions from electron-phonon processes and self-heating effects are relatively small, therefore IF roll-off will be governed by the phonon-escape.Two independent experiments were performed at GARD and MSPU on a similar experimental setup at frequencies of approximately 180 and 140 GHz, respectively, and have shown reproducible and consistent results. The entire IF chain was characterized by S-parameter measurements. We compared the measurement results of epitaxial NbN grown onto GaN buffer-layer with Tc of 12.5 K (4.5nm) with high quality polycrystalline NbN films on Si substrate with Tc of 10.5K (5nm) and observed a strong indication of an enhancement of phonon escape to the substrate by a factor of two for the NbN/GaN material combination.
	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	1202
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	Author	Shcherbatenko, M.; Lobanov, Y.; Kovalyuk, V.; Korneev, A.; Gol'tsman, G. N.
	Title	Photon counting detector as a mixer with picowatt local oscillator power requirement			Type	Conference Article
	Year	2016	Publication	Proc. 27^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 27^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	110
	Keywords	SSPD mixer, SNSPD
	Abstract	At the current stage of the heterodyne receiver technology, great attention is paid to the development of detector arrays and matrices comprising many detectors on a single wafer. However, any traditional THz detector (such as SIS, HEB, or Schottky diode) requires quite a noticeable amount of Local Oscillator (LO) power which scales with the matrix size, and the total amount of the LO power needed is much greater than that available from compact and handy solid state sources. Substantial reduction of the LO power requirement may be obtained with a photon-counting detector used as a mixer. This approach, mentioned earlier in [1,2] provides a number of advantages. Thus, sensitivity of such a detector would be at the quantum limit (because of the photon-counting nature of the detector) and just a few LO photons for the mixing would be required leading to a possible breakthrough in the matrix receiver development. In addition, the receiver could be easily tuned from the heterodyne to the direct detection mode without any loss in its sensitivity with the latter limited only by the quantum efficiency of the detector used. We demonstrate such a technique with the use of the Superconducting Nanowire Single Photon Detector(SNSPD)[3] irradiated by both 1.5 μm LO with a tiny amount of power (from a few picowatts down to femtowatts) facing the detector, and the test signal with a power significantly less than that of the LO. The SNSPD was operated in the current mode and the bias current was slightly below its critical value. Irradiating the detector with either the LO or the signal source produced voltage pulses which are statistically evenly distributed and could be easily counted by a lab counter or oscilloscope. Irradiating the detector by the both lasers simultaneously produced pulses at the frequency f m which is the exact difference between the frequencies at which the two lasers operate. f m could be deduced form either counts statistics integrated over a sufficient time interval or with the help of an RF spectrum analyzer. In addition to the chip SNSPD with normal incidence coupling, we use the detectors with a travelling wave geometry design [4]. In this case a niobium nitride nanowire is placed on the top of a nanophotonic waveguide, thus increasing the efficient interaction length. Integrated device scheme allows us to measure the optical losses with high accuracy. Our approach is fully scalable and, along with a large number of devices integrated on a single chip can be adapted to the mid and far IR ranges. This work was supported in part by the Ministry of Education and Science of the Russian Federation, contract no. 14.B25.31.0007 and by RFBR grant # 16-32-00465. 1. Leaf A. Jiang and Jane X. Luu, ―Heterodyne detection with a weak local oscillator, Applied Optics Vol. 47, Issue 10, pp. 1486-1503 (2008) 2. Matsuo H. ―Requirements on Photon Counting Detectors for Terahertz Interferometry J Low Temp Phys (2012) 167:840–845 3. A. Semenov, G. Gol'tsman, A. Korneev, “Quantum detection by current carrying superconducting film”, Physica C, 352, pp. 349-356 (2001) 4. O. Kahl, S. Ferrari, V. Kovalyuk, G. N. Goltsman, A. Korneev, and W. H. P. Pernice, ―Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths., Sci. Rep., vol. 5, p. 10941, (2015).
	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	1203
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	Author	Ryabchun, S. A.; Tretyakov, I. V.; Finkel, M. I.; Maslennikov, S. N.; Kaurova, N. S.; Seleznev, V. A.; Voronov, B. M.; Gol'tsman, G. N.
	Title	NbN phonon-cooled hot-electron bolometer mixer with additional diffusion cooling			Type	Conference Article
	Year	2009	Publication	Proc. 20^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 20th ISSTT
	Volume		Issue		Pages	151-154
	Keywords	HEB, mixer, bandwidth, noise temperatue, in-situ contacts, in situ contacts
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Charlottesville, USA	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	590
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	Author	Lobanov, Y.; Tong, C.; Blundell, R.; Gol'tsman, G.
	Title	A study of direct detection effect on the linearity of hot electron bolometer mixers			Type	Conference Article
	Year	2009	Publication	Proc. 20^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 20th ISSTT
	Volume		Issue		Pages	282-287
	Keywords	HEB mixer, direct detection effect
	Abstract	We have performed a study of how direct detection affects the linearity and hence the calibration of an HEB mixer. Two types of waveguide HEB devices have been used: a 0.8 THz HEB mixer and a 1.0 THz HEB mixer which is ~5 times smaller than the former. Two independent experimental approaches were used. In the Î”G/G method, the conversion gain of the HEB mixer is first measured as a function of the bias current for a number of bias voltages. At each bias setting, we carefully measure the change in the operating current when the input loads are switched. From the measured data, we can derive the expected difference in gain between the hot and cold loads. In the second method (injection method [1]), the linearity of the HEB mixer is independently measured by injecting a modulated signal for different input load temperatures. The results of both approaches confirm that there is gain compression in the operation of HEB mixers. Based on the results of our measurements, we discuss the impact of direct detection effects on the operation of HEB mixers.
	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	RPLAB @ gujma @			Serial	724
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	Author	Smirnov, A. V.; Larionov, P. A.; Finkel, M. I.; Maslennikov, S. N.; Voronov, B. M.; Gol'tsman, G. N.
	Title	NbZr films for THz phonon-cooled HEB mixers			Type	Conference Article
	Year	2008	Publication	Proc. 19^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 19^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	44-47
	Keywords	HEB, NbZr, material search
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Groningen, Netherlands	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	577
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	Author	Maslennikov, S. N.; Finkel, M. I.; Antipov, S. V.; Polyakov, S. L.; Zhang, W.; Ozhegov, R.; Vachtomin, Yu. B.; Svechnikov, S. I.; Smirnov, K. V.; Korotetskaya, Yu. P.; Kaurova, N. S.; Gol'tsman, G. N.; Voronov, B. M.
	Title	Spiral antenna coupled and directly coupled NbN HEB mixers in the frequency range from 1 to 70 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	177-179
	Keywords	directly coupled NbN HEB mixers
	Abstract	We investigate both antenna coupled and directly coupled HEB mixers at several LO frequencies within the range of 2.5 THz to 70 THz. H20 (2.5+10.7 THz), and CO2 (30 THz) gas discharge lasers are used as the local oscillators. The noise temperature of antenna coupled mixers is measured at LO frequencies of 2.5 THz, 3.8 THz, and 30 THz. The results for both antenna coupled and directly coupled mixer types are compared. The devices with in—plane dimensions of 5x5 ,um 2 are pumped by LO radiation at 10.7 THz. The directly coupled HEB demonstrates nearly flat dependence of responsivity on frequency in the range of 25+64 THz.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Paris, France	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	386
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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	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	Finkel, M. I.; Maslennikov, S. N.; Vachtomin, Yu. B.; Svechnikov, S. I.; Smirnov, K. V.; Seleznev, V. A.; Korotetskaya, Yu. P.; Kaurova, N. S.; Voronov, B. M.; Gol'tsman, G. N.
	Title	Hot electron bolometer mixer for 20 – 40 THz frequency 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	393-397
	Keywords	IR NbN HEB mixers
	Abstract	The developed HEB mixer was based on a 5 nm thick NbN film deposited on a GaAs substrate. The active area of the film was patterned as a 30×20 μm 2 strip and coupled with a 50 Ohm coplanar line deposited in situ. An extended hemispherical germanium lens was used to focus the LO radiation on the mixer. The responsivity of the mixer was measured in a direct detection mode in the 25÷64 THz frequency range. The noise performance of the mixer and the directivity of the receiver were investigated in a heterodyne mode. A 10.6 μm wavelength CW CO 2 laser was utilized as a local oscillator.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Göteborg, Sweden	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	369
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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	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	Vachtomin, Y. B.; Antipov, S. V.; Maslennikov, S. N.; Smirnov, K. V.; Polyakov, S. L.; Kaurova, N. S.; Grishina, E. V.; Voronov, B. M.; Gol'tsman, G. N.
	Title	Noise temperature measurements of NbN phonon-cooled hot electron bolometer mixer at 2.5 and 3.8 THz			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	236-241
	Keywords	HEB mixer, NbN, direct detection effect
	Abstract	We present the results of noise temperature measurements of NbN phonon-cooled HEB mixers based on a 3.5 nm NbN film deposited on a high-resistivity Si substrate with a 200 nm – thick MgO buffer layer. The mixer element was integrated with a log-periodic spiral antenna. The noise temperature measurements were performed at 2.5 THz and at 3.8 THz local oscillator frequencies for the 3 µm x 0.2 µm active area devices. The best uncorrected receiver noise temperatures found for these frequencies are 1300 K and 3100 K, respectively. A water vapour discharge laser was used as the LO source. We also present the results of direct detection contribution to the measured Y-factor and of a possible error of noise temperature calculation. This error was more than 8% for the mixer with in-plane dimensions of 2.4 x 0.16 µm 2 at the optimal noise temperature point. The use of a mesh filter enabled us to avoid the effect of direct detection and decrease optical losses by 0.5 dB. The paper is concluded by the investigation results of the mixer polarization response. It was shown that the polarization can differ from the circular one at 3.8 THz by more than 2 dB.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Northampton, Massachusetts, USA	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	344
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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	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	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	Meledin, D.; Tong, C. Y.-E.; Blundell, R.; Kaurova, N.; Smirnov, K.; Voronov, B.; Gol'tsman, G.
	Title	The sensitivity and IF bandwidth of waveguide NbN hot electron bolometer mixers on MgO buffer layers over crystalline quartz			Type	Conference Article
	Year	2002	Publication	Proc. 13^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 13^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	65-72
	Keywords	waveguide NbN HEB mixers
	Abstract	We have developed and characterized waveguide phonon-cooled NbN Hot Electron Bolometer (FMB) mixers fabricated from a 3-4 nm thick NbN film deposited on a 200nm thick MgO buffer layer over crystalline quartz. Double side band receiver noise temperatures of 900-1050 K at 1.035 THz, and 1300-1400 K at 1.26 THz have been measured at an intermediate frequency of 1.5 GHz. The intermediate frequency bandwidth, measured at 0.8 THz LO frequency, is 3.2 GHz at the optimal bias point for low noise receiver operation.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Cambridge, MA, USA	Editor	Harvard university
	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	326
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	Author	Cherednichenko, S.; Kroug, M.; Khosropanah, P.; Adam, A.; Merkel, H.; Kolberg, E.; Loudkov, D.; Voronov, B.; Gol'tsman, G.; Richter, H.; Hübers, H. W.
	Title	A broadband terahertz heterodyne receiver with an NbN HEB mixer			Type	Conference Article
	Year	2002	Publication	Proc. 13^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 13^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	85-95
	Keywords	NbN HEB mixers
	Abstract	We present a broadband and low noise heterodyne receiver for 1.4-1.7 THz designed for the Hershel Space Observatory. A phonon- cooled NbN HEB mixer was integrated with a normal metal double- slot antenna and an elliptical silicon lens. DSB receiver noise temperature Tr was measured from 1 GHz through 8GHz intermediate frequency band with 50 MHz instantaneous bandwidth. At 4.2 K bath temperature and at 1.6 THz LO frequency Tr is 800 K with the receiver noise bandwidth of 5 GHz. While at 2 K bath temperature Tr was as low as 700 K. At 0.6 THz and 1.1 THz a spiral antenna integrated NbN HEB mixer showed the receiver noise temperature 500 K and 800 K, though no antireflection coating was used in this case. Tr of 1100 K was achieved at 2.5 THz while the receiver noise bandwidth was 4 GHz.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Cambridge, MA, USA	Editor	Harward University
	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	332
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	Author	Verevkin, A.; Zhang, J.; Slysz, W.; Sobolewski, Roman; Lipatov, A.; Okunev, O.; Chulkova, G.; Korneev, A.; Smimov, K.; Gol'tsman, G. N.
	Title	Spectral sensitivity and temporal resolution of NbN superconducting single-photon detectors			Type	Conference Article
	Year	2002	Publication	Proc. 13^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 13^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	105-111
	Keywords	NbN SSPD, SNSPD
	Abstract	We report our studies on spectral sensitivity and time resolution of superconducting NbN thin film single-photon detectors (SPDs). Our SPDs exhibit an everimentally measured detection efficiencies (DE) from — 0.2% at 2=1550 nm up to —3% at lambda=405 nm wavelength for 10-nm film thickness devices and up to 3.5% at lambda=1550 nm for 3.5-nm film thickness devices. Spectral dependences of detection efficiency (DE) at 2=0.4 —3.0 pm range are presented. With variable optical delay setup, it is shown that NbN SPD potentially can resolve optical pulses with the repetition rate up to 10 GHz at least. The observed full width at the half maximum (FWHM) of the signal pulse is about 150-180 ps, limited by read-out electronics. The jitter of NbN SPD is measured to be —35 ps at optimum biasing.
	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	1528
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	Author	Loudkov, D.; Khosropanah, P.; Cherednichenko, S.; Adam, A.; MerkeI, H.; Kollberg, E.; Gol'tsman, G.
	Title	Broadband fourier transform spectrometer (FTS) measurements of spiral and double-slot planar antennas at THz frequencies			Type	Conference Article
	Year	2002	Publication	Proc. 13^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 13^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	373-369
	Keywords	NbN HEB mixers
	Abstract	The direct responses of NbN phonon-cooled hot electron bolometer (HEB) mixers, integrated with different planar antennas, are measured, using Fourier Transform Spectrometer (F1S). One spiral antenna and several double slot antennas, designed for 0.6, 1.4, 1.6, 1.8 and 2.5 THz central frequencies, are investigated. The Optimization of the measurement set-up is discussed in terms of the beam splitter and the F11S-to-HEB coupling. The result shows that the spiral antenna is circular polarized and has a bandwidth of about 2 THz. The frequency bands of double slot antennas show some shift from the design values and their relative bandwidth increases by increasing the design frequency. The antenna responses do not depend on the HEB bias point and temperature, as long as the device is in the resistive state.
	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	1530
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	Author	Cherednichenko, S.; Kroug, M.; Merkel, H.; Kollberg, E.; Loudkov, D.; Smirnov, K.; Voronov, B.; Gol'tsman, G.; Gershenzon, E.
	Title	Local oscillator power requirement and saturation effects in NbN HEB mixers			Type	Conference Article
	Year	2001	Publication	Proc. 12^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 12^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	273-285
	Keywords	NbN HEB mixers, LO power, local oscillator power, saturation effect, dynamic range
	Abstract	The local oscillator power required for NbN hot-electron bolometric mixers (P LO ) was investigated with respect to mixer size, critical temperature and ambient temperature. P LO can be decreased by a factor of 10 as the mixer size decreases from 4×0.4 µm 2 to 0.6×0.13 µm 2 . For the smallest volume mixer the optimal local oscillator power was found to be 15 nW. We found that for such mixer no signal compression was observed up to an input signal of 2 nW which corresponds to an equivalent input load of 20,000 K. For a constant mixer volume, reduction of T c can decrease optimal local oscillator power at least by a factor of 2 without a deterioration of the receiver noise temperature. Bath temperature was found to have minor effect on the receiver characteristics.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	San Diego, CA, USA	Editor	Jet Propulsion Laboratory, California Inst.it.u.t.e of Technology
	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	318
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	Author	Kroug, M.; Cherednichenko, S.; Choumas, M.; Merkel, H.; Kollberg, E.; Hübers, H.-W.; Richter, H.; Loudkov, D.; Voronov, B.; Gol'Tsman, G.
	Title	HEB quasi-optical heterodyne receiver for THz frequencies			Type	Conference Article
	Year	2001	Publication	Proc. 12^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal
	Volume		Issue		Pages	244-252
	Keywords	HEB mixer, NbN, MgO, conversion gain bandwidth, noise temperature
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	San Diego, CA, USA	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	319
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	Author	Hübers, H.-W.; Semenov, A. D.; Richter, H.; Schubert, J.; Hadjiloucas, S.; Bowen, J. W.; Gol'tsman, G.; Voronov, B. M.; Gershenzon, E. M.
	Title	Antenna pattern of the quasi-optical hot-electron bolometric mixer at terahertz frequencies			Type	Conference Article
	Year	2001	Publication	Proc. 12^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 12^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	286-296
	Keywords	NbN HEB mixers
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	San Diego, CA, USA	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	323
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	Author	Semenov, A. D.; Hübers, H.–W.; Schubert, J.; Gol'tsman, G. N.; Elantiev, A. I.; Voronov, B. M.; Gershenzon, E. M.
	Title	Frequency dependent noise temperature of the lattice cooled hot-electron terahertz mixer			Type	Conference Article
	Year	2000	Publication	Proc. 11^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 11^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	39-48
	Keywords	NbN HEB mixers
	Abstract	We present the measurements and the theoretical model on the frequency dependent noise temperature of a lattice cooled hot electron bolometer (HEB) mixer in the terahertz frequency range. The experimentally observed increase of the noise temperature with frequency is a cumulative effect of the non-uniform distribution of the high frequency current in the bolometer and the charge imbalance, which occurs near the edges of the normal domain and contacts with normal metal. In addition, we present experimental results which show that the noise temperature of a HEB mixer can be reduced by about 30% due to a Parylene antireflection coating on the Silicon hyperhemispheric lens.
	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	305
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	Author	Cherednichenko, S.; Ronnung, F.; Gol'tsman, G.; Gershenzon, E.; Winkler, D.
	Title	YBa₂Cu₃O_7-δ hot-electron bolometer with submicron dimensions			Type	Conference Article
	Year	1999	Publication	Proc. 10^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 10^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	181-189
	Keywords	YBCO HTS HEB mixers
	Abstract	Photoresponse of YBa₂Cu₃O_7-δ hot-electron bolometers to modulated near-infrared radiation was studied at a modulation .frequenc y var y ing from 0.2 MHz to 2 GHz. Bolometers were _fabricated from a 50 12 M thick film and had in-plane areas of 10x10 , um 2 . 2x0.2 s um', 1x0.2 p.m', and 0.5x0.2 jim. We found that nonequilibrium phonons cool down more effectively for the bolometers with smaller area. For the smallest bolometer the bolometric component in the response is 10 dB less than for the largest one.
	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	1572
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	Author	Schubert, J.; Semenov, A.; Gol'tsman, G.; Hübers, H.-W.; Schwaab, G.; Voronov, B.; Gershenzon, E.
	Title	Noise temperature and sensitivity of a NbN hot-electron mixer at frequencies from 0.7 THz to 5.2 THz			Type	Conference Article
	Year	1999	Publication	Proc. 10^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 10^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	190-199
	Keywords	NbN HEB mixers
	Abstract	We report on noise temperature measurements of a NbN phonon-cooled hot-electron bolometric mixer at different bias regimes. The device was a 3 nm thick bridge with in-plane dimensions of 1.7 x 0.2 gm 2 integrated in a complementary logarithmic spiral antenna. Measurements were performed at frequencies ranging from 0.7 THz up to 5.2 THz. The measured DSB noise temperatures are 1500 K (0.7 THz), 2200 K (1.4 THz), 2600 K (1.6 THz), 2900 K (2.5 THz), 4000 K (3.1 THz) 5600 K (4.3 THz) and 8800 K (5.2 THz). Two bias regimes are possible in order to achieve low noise temperatures. But only one of them yields sensitivity fluctuations close to the theoretical limit.
	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	1573
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	Author	Gerecht, E.; Musante, C. F.; Jian, H.; Zhuang, Y.; Yngvesson, K. S.; Dickinson, J.; Goyette, T.; Waldman, J.; Yagoubov, P. A.; Gol'tsman, G. N.; Voronov, B. M.; Gershenzon, E. M.
	Title	Improved characteristics of NbN HEB mixers integrated with log-periodic antennas			Type	Conference Article
	Year	1999	Publication	Proc. 10^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 10^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	200-207
	Keywords	NbN HEB mixers
	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
	Notes				Approved	no
	Call Number				Serial	1574
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	Author	Yagoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Hübers, H.-W.; Schubert, J.; Schwaab, G.; Gol'tsman, G.; Gershenzon, E.
	Title	NbN hot electron bolometric mixers at frequencies between 0.7 and 3.1 THz			Type	Conference Article
	Year	1999	Publication	Proc. 10^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 10^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	238-246
	Keywords	NbN HEB mixers
	Abstract	The performance of NbN based phonon-cooled Hot Electron Bolometric (HEB) quasioptical mixers is investigated in the 0.7-3.1 THz frequency range. The devices are made from a 3.5-4 nm thick NbN film on high resistivity Si and integrated with a planar spiral antenna on the same substrate. The length of the bolometer microbridge is 0.1- 0.2 gm, the width is 1-2 gm. The best results of the DSB receiver noise temperature measured at 1.5 GHz intermediate frequency are: 800 K at 0.7 THz, 1100 K at 1.6 THz, 2000 K at 2.5 THz and 4200 K at 3.1 THz. The measurements were performed with a far infrared laser as the local oscillator (LO) source. The estimated LO power required is less than 500 nW at the receiver input. First results on the spiral antenna polarization measurements are reported.
	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	1575
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	Author	Il'in, K. S.; Gol'tsman, G. N.; Voronov, B. M.; Sobolewski, Roman
	Title	Characterization of the electron energy relaxation process in NbN hot-electron devices			Type	Conference Article
	Year	1999	Publication	Proc. 10^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 10^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	390-397
	Keywords	HEB mixers, SSPD, SNSPD, NbN films, Nb films
	Abstract	We report on transient measurements of electron energy relaxation in NbN films with 300-fs time resolution. Using an electro-optic sampling technique, we have studied the photoresponse of 3.5-nm-thick NbN films deposited on sapphire substrates and exposed to 100-fs-wide optical pulses. Our experimental data analysis was based on the two-temperature model and has shown that in our films at the superconducting transition 10.5 K the inelastic electron-phonon scattering time was about (111}+-__.2) ps. This response time indicated that the maximum intermediate-frequency band of a NbN hot-electron phonon-cooled mixer should reach (16+41-3) GHz if one eliminates the bolometric phonon-heating effect. We have suggested several ways to increase the effectiveness of phonon cooling to achieve the above intrinsic value of the NbN mixer bandwidth.
	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	1576
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	Author	Schwaab, G. W.; Hübers, H.-W.; Schubert, J.; Erichsen, Patrik; Gol'tsman, G.; Semenov, A.; Verevkin, A.; Cherednichenko, S.; Gershenzon, E.
	Title	A high resolution spectrometer for the investigation of molecular structures in the THZ range			Type	Conference Article
	Year	1999	Publication	Proc. 10^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 10^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	530-538
	Keywords	antireflection coatings, dielectric mirrors
	Abstract	A status report on the design study of a novel tunable far-infrared (TuFTR) spectrometer for the investigation of the structure of weakly bound molecular complexes is given. The goal is a sensitive TuFIR spectrometer with full frequency coverage from 1-6 THz. To hit the goal, advanced sources (e.g. p-Ge lasers) and detectors (e.g. superconducting hot electron bolometric (HEB) mixers) shall be employed to extend the technique of cavity ringdown spectroscopy, that is currently used at optical and infrared frequencies to the FIR spectral range. Critical for such a system are high-Q resonators that still allow good optical coupling, and wideband antireflection coatings to increase detector sensitivity and decrease optical path losses. 2 nd order effective media theory and an iterative multilayer algorithm have been employed to design wideband antireflection coatings for dielectrics with large dielectric constants like Ge or Si. Taking into account 6 layers, for Si bandwidths of 100% of the center frequency could be obtained with power reflectivities below 1% for both polarizations simultaneously. Wideband dielectric mirrors including absorption losses were also studied yielding a bandwidth of about 50% with reflectivities larger than 99.5%.
	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	1577
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	Author	Gerecht, E.; Musante, C. F.; Jian, H.; Yngvesson, K. S.; Dickinson, J.; Waldman, J.; Gol'tsman, G. N.; Yagoubov, P. A.; Voronov, B. M.; Gershenzon, E. M.
	Title	Measured results for NbN phonon-cooled hot electron bolometric mixers at 0.6-0.75 THz, 1.56 THz, and 2.5 THz			Type	Conference Article
	Year	1998	Publication	Proc. 9^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 9^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	105-114
	Keywords	NbN HEB mixers
	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
	Notes				Approved	no
	Call Number				Serial	1587
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	Author	Svechnikov, S.; Verevkin, A.; Voronov, B.; Menschikov, E.; Gershenzon, E.; Gol'tsman, G.
	Title	Quasioptical phonon-cooled NbN hot electron bolometer mixers at 0.5-1.1 THz			Type	Conference Article
	Year	1998	Publication	Proc. 9^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 9^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	45-51
	Keywords	NbN HEB mixers
	Abstract	The noise performance of a receiver incorporating spiral antenna coupled NbN phonon-cooled superconducting hot electron bolometric mixer is measured from 450 GHz to 1200 GHz. The mixer element is thin (thickness nm) NbN 1.5 pm wide and 0.2 i.um long film fabricated by lift-off e-beam lithography on high-resistive silicon substrate. The noise of the receiver temperature is 1000 K at 800-900 GHz, 1200 K at 950 GHz, and 1600 K at 1.08 THz. The required (absorbed) local-oscillator power is —20 nW.
	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	1586
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	Author	Gousev, Yu. P.; Olsson, H. K.; Gol'tsman, G. N.; Voronov, B. M.; Gershenzon, E. M.
	Title	NbN hot-electron mixer at radiation frequencies between 0.9 THz and 1.2 THz			Type	Conference Article
	Year	1998	Publication	Proc. 9^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 9^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	121-129
	Keywords	NbN HEB mixers
	Abstract	We report on noise temperature measurements for a NbN phonon-cooled hot-electron mixer at radiation frequencies between 0.9 THz and 1.2 THz. Radiation was coupled to the mixer, placed in a vacuum chamber of He cryostat, by means of a planar spiral antenna and a Si immersion lens. A backward-wave oscillator, tunable throughout the spectral range, delivered an output power of few 1.1W that was enough for optimum operation of the mixer. At 4.2 K ambient temperature and 1.025 THz radiation frequency, we obtained a receiver noise temperature of 1550 K despite of using a relatively noisy room-temperature amplifier at the intermediate frequency port. The noise temperature was fairly constant throughout the entire operation range and for intermediate frequencies from 1 GHz to 2 GHz.
	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	1588
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	Author	Yazoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Gol'tsman, G.; Lipatov, A.; Svechnikov, S.; Gershenzon, E.
	Title	Quasioptical NbN phonon-cooled hot electron bolometric mixers with low optimal local oscillator power			Type	Conference Article
	Year	1998	Publication	Proc. 9^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 9^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	131-140
	Keywords	NbN HEB mixers
	Abstract	In this paper, the noise perform.ance of NIN based phonon-cooled Hot Electron Bolometric (HEB) quasioptical mixers is investigated in the 0.55-1.1 THz frequency range. The best results of the DSB noise temperature are: 500 K at 640 GHz, 600 K at 750 GHz, 850 K at 910 GHz and 1250 K at 1.1 THz. The water vapor in the signal path causes a significant contribution to the measured noise temperature around 1.1 THz. The required LO power is typically about 60 nW. The frequency response of the spiral antenna+lens system is measured using a Fourier Transform Spectrometer with the HEB operating in a detector mode.
	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	1589
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	Author	Il'in, K. S.; Cherednichenko, S. I.; Gol'tsman, G. N.; Currie, M.; Sobolewski, R.
	Title	Comparative study of the bandwidth of phonon-cooled NbN hot-electron bolometers in submillimeter and optical wavelength ranges			Type	Conference Article
	Year	1998	Publication	Proc. 9^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 9^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	323-330
	Keywords	NbN HEB mixers
	Abstract	We report the results of the bandwidth measurements of NbN hot-electron bolometers, perfomied in the terahertz frequency domain at 140 GHz and 660 GHz and in time domain in the optical range at the wavelength of 395 nm.. Our studies were done on 3.5-nm-thick NbN films evaporated on sapphire substrates and patterned into ilin-size microbridges. In order to measure the gain bandwidth, we used two identical BWOs (140 or 660 GHz), one functioning as a local oscillator and the other as a signal source. The bandwidth we achieved was 3.5-4 GHz at 4.2 K with the optimal LO and DC biases. Time-domain measurements with a resolution below 300 fs were performed using an electro-optic sampling system, in the temperature range between 4.2 K to 9 K at various values of the bias current and optical power. The obtained response time of the NbN hot-electron bolometer to —100- fs-wide Ti:sapphire laser pulses was about 27 ps, what corresponds to the 5.9 GHz gain bandwidth.
	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	1590
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	Author	Cherednichenko, S.; Yagoubov, P.; Il'In, K.; Gol'tsman, G.; Gershenzon, E.
	Title	Large bandwidth of NbN phonon-cooled hot-electron bolometer mixers on sapphire substrates			Type	Conference Article
	Year	1997	Publication	Proc. 8^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 8^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	245-257
	Keywords	NbN HEB mixers, fabrication process
	Abstract	The bandwidth of NbN phonon-cooled hot electron bolometer mixers has been systematically investigated with respect to the film thickness and film quality variation. The films, 2.5 to 10 mm thick, were fabricated on sapphire substrates using DC reactive magnetron sputtering. All devices consisted of several parallel strips, each 1 1.1 wide and 211 long, placed between Ti-Au contact pads. To measure the gain bandwidth we used two identical BWOs operating in the 120-140 GHz frequency range, one functioning as a local oscillator and the other as a signal source. The majority of the measurements were made at an ambient temperature of 4.5 K with optimal LO and DC bias. The maximum 3 dB bandwidth (about 4 GHz) was achieved for the devices made of films which were 2.5-3.5 nm thick, had a high critical temperature, and high critical current density. A theoretical analysis of bandwidth for these mixers based on the two-temperature model gives a good description of the experimental results if one assumes that the electron temperature is equal to the critical 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	276
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	Author	Kawamura, J.; Blundell, R.; Tong, C-Y. E.; Gol'tsman, G.; Gershenzon, E.; Voronov, B.; Cherednichenko, S.
	Title	Phonon-cooled NbN HEB mixers for submillimeter wavelengths			Type	Conference Article
	Year	1997	Publication	Proc. 8^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 8^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	23-28
	Keywords	waveguide NbN HEB mixers
	Abstract	The noise performance of receivers incorporating NbN phonon-cooled superconducting hot electron bolometric mixers is measured from 200 GHz to 900 GHz. The mixer elements are thin-film (thickness — 4 nm) NbN with —5 to 40 pm area fabricated on crystalline quartz sub- strates. The receiver noise temperature from 200 GHz to 900 GHz demonstrates no unexpected degradation with increasing frequency, being roughly TRx ,; 1-2 K The best receiver noise temperatures are 410 K (DSB) at 430 GHz, 483 K at 636 GHz, and 1150 K at 800 GHz.
	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	275
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	Author	Ekström, H.; Kollberg, E.; Yagoubov, P.; Gol'tsman, G.; Gershenzon, E.; Yngvesson, S.
	Title	Phonon cooled ultra thin NbN hot electron bolometer mixers at 620 GHz			Type	Conference Article
	Year	1997	Publication	Proc. 8^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 8^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	29-35
	Keywords	NbN HEB mixers
	Abstract	We have measured the noise performance and gain bandwidth of 35 A thin NbN hot-electron mixers integrated with spiral antennas on silicon substrate lenses at 620 GHz. A double-sideband receiver noise temperature less than 1300 K has been obtained with a 3 dB bandwidth of GHz. The gain bandwidth is 3.2 GHz. A lower noise temperature of 1100 K has been achieved with an improved set-up. The mixer output noise dominated by thermal fluctuations is about 50-60 K, and the SSB receiver and intrinsic conversion gain is about -18 and -12 dB, respectively. Without mismatch losses and excluding the loss from the beamsplitter, we expect to achieve a receiver noise temperature of less than 700 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	1604
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	Author	Gerecht, E.; Musante, C. F.; Wang, Z.; Yngvesson, K. S.; Waldman, J.; Gol'tsman, G. N.; Yagoubov, P. A.; Svechnikov, S. I.; Voronov, B. M.; Cherednichenko, S. I.; Gershenzon, E. M.
	Title	NbN hot electron bolometric mixer for 2.5 THz: the phonon cooled version			Type	Conference Article
	Year	1997	Publication	Proc. 8^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 8^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	258-271
	Keywords	NbN HEB mixers
	Abstract	We describe an investigation of a NbN HEB mixer for 2.5 THz. NbN HEBs are phonon-cooled de-. vices which are expected, according to theory, to achieve up to 10 GHz IF conversion gain bandwidth. We have developed an antenna coupled device using a log-periodic antenna and a silicon lens. We have demon- strated that sufficient LO power can be coupled to the device in order to bring it to the optimum mixer oper- ating point. The LO power required is less than 1 microwatts as measured directly at the device. We also describe the impedance characteristics of NbN devices and compare them with theory. The experimental results agree with theory except for the imaginary part of the impedance at very low frequencies as was demonstrated by other groups.
	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	1605
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	Author	Yagubov, P.; Gol'tsman, G.; Voronov, B.; Seidman, L.; Siomash, V.; Cherednichenko, S.; Gershenzon, E.
	Title	The bandwidth of HEB mixers employing ultrathin NbN films on sapphire substrate			Type	Conference Article
	Year	1996	Publication	Proc. 7^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 7^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	290-302
	Keywords	NbN HEB mixers, fabrication process
	Abstract	We report on some unusual features observed during fabrication of ultrathin NbN films with high Tc. The films were used to fabricate HEB mixers, which were evaluated for IF bandwidth measurements at 140 GHz. Ultrathin films were fabricated using reactive dc magnetron sputtering with a discharge current source. Reproducible parameters of the films are assured keeping constant the difference between the discharge voltage in pure argon, and in a gas mixture, for the same current. A maximum bandwidth of 4 GHz at optimal LO and dc bias was obtained for mixer chip based on NbN film 35 A thick with Tc = 11 K.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Charlottesville, Virginia, USA	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	266
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	Author	Yagoubov, P.; Gol'tsman, G.; Voronov, B.; Svechnikov, S.; Cherednichenko, S.; Gershenzon, E.; Belitsky, V.; Ekström, H.; Semenov, A.; Gousev, Yu.; Renk, K.
	Title	Quasioptical phonon-cooled NbN hot-electron bolometer mixer at THz frequencies			Type	Conference Article
	Year	1996	Publication	Proc. 7^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 7^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	303-317
	Keywords	NbN HEB mixers
	Abstract	In our experiments we tested phonon-cooled hot-electron bolometer (HEB) quasioptical mixer based on spiral antenna designed for 0.5-1.2 THz frequency band and fabricated on sapphire, Si-coated sapphire and high resistivity silicon substrates. HEB devices were produced from thin superconducting NbN film 3.5-6 nm thick with the critical temperature of about 11-12 K. For these devices we achieved the receiver noise temperature T R (DSB) = 3000 K in the 500-700 GHz frequency range and an IF bandwidth of 3-4 GHz. Prelimanary measurements at frequencies 1-1.2 THz resulted the receiver noise temperature about 9000 K (DSB).
	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	1614
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	Author	Trifonov, V. A.; Karasik, B. S.; Zorin, M. A.; Gol'tsman, G. N.; Gershenzon, E. M.; Lindgren, M.; Danerud, M.; Winkler, D.
	Title	9.6 μm wavelength mixing in a patterned YBa₂Cu₃O_7-δ thin film			Type	Conference Article
	Year	1996	Publication	Proc. 7^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 7^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	337-348
	Keywords	YBCO HTS HEB mixers
	Abstract	Hot-electron bolometric (HEB) mixing of 9.6 gm infrared radiation from two lasers in high-quality YBa2Cu307_3 (YBCO) patterned thin film has been demonstrated. A heterodyne measurement showed an intermediate frequency (IF) bandwidth of 18 GHz, limited by our measurement system. An intrinsic limit of 100 GHz is predicted. Between 0.1 and 1 GHz intermediate frequency, temperature fluctuations with an equivalent output noise temperature Tfl up to -150 K, contributed to the mixer noise while Johnson noise dominated above 1 GHz. The overall conversion loss at 77 K at low intermediate frequencies was measured to be -25 dB, of which 13 dB was due to the coupling loss. The IIEB mixer is very promising for use in heterodyne receivers within the whole infrared 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		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1615
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	Author	Gerecht, E.; Musante, C. F.; Wang, Z.; Yngvesson, K. S.; Mueller, E. R.; Waldman, J.; Gol'tsman, G. N.; Voronov, B. M.; Cherednichenco, S. I.; Svechnikov, S. I.; Yagoubov, P. A.; Gershenzon, E. M.
	Title	Optimization of hot eleciron bolometer mixing efficiency in NbN at 119 micrometer wavelength			Type	Conference Article
	Year	1996	Publication	Proc. 7^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 7^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	584-600
	Keywords	NbN HEB mixers
	Abstract	We describe an investigation of a NbN HEB mixer for 2.5 THz. An intrinsic conversion loss of 23 dB has been measured with a two-laser measurement technique. The conversion loss was limited by the LO power available and is expected to decrease to 10 dB or less when sufficient LO power is available. For this initial experiment we used a prototype device which is directly coupled to the laser beams. We present results for a back-short technique that improves the optical coupling to the device and describe our progress for an antenna-coupled device with a smaller dimension. Based on our measured data for conversion loss and device output noise level, we predict that NbN HEB mixers will be capable of achieving DSB receiver noise temperatures of ten times the quantum noise limit in the THz 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		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1616
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	Author	Okunev, 0.; Dzardranov, A.; Gol'tsman, G.; Gershenzon, E.
	Title	Performances of hot—electron superconducting mixer for frequencies less than the gap energy: NbN mixer for 100 GHz operation			Type	Conference Article
	Year	1995	Publication	Proc. 6^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 6^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	247-253
	Keywords	NbN HEB mixers
	Abstract	The possibilities to improve the parameters of the 100 GHz NbN HEB superconducting waveguide mixers have been studied. The device consists of a signal strip 1 gm wide by 2 Am long made of 40 A thick NbN film. The best operation point was found at 5 K, where the mixer bandwidth made up 1.5-2 GHz and the total loss diminished down to 8 dB. The critical current density has been increased up to " 40 6 A/cm 2 , the noise temperature of the receiver (DSB) has reduced down to 450 K and the local oscillator power has decreased down to -.4).1 mcV.
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	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
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	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1625
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	Author	Kawamura, J.; Blundell, R.; Tong, C.-Y. E.; Gol'tsman, G.; Gershenzon, E.; Voronov, B.
	Title	NbN hot-electron mixer measurements at 200 GHz			Type	Conference Article
	Year	1995	Publication	Proc. 6^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 6^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	254-261
	Keywords	NbN HEB mixers
	Abstract	We present noise and gain measurements of resistively driven NbN hot-electron mixers near 200 GHz. The device geometry is chosen so that the dominant cooling process of the hot-electrons is their interaction with the lattice. Except for a single batch, the intermediate frequency cut-off of these mixer elements is – 3 700 MHz, and has shown little variation among other batches of devices. At 100 MHz we measured intrinsic mixer losses as low as —3 dB. We measured the noise temperatures at several intermediate frequencies, and for the best de- vice at 137 MHz with 20 MHz bandwidth, we measured 2000 K; using a low-noise first- stage amplifier at 1.5 GHz with 200 MHz bandwidth, the receiver noise temperature measured 2800 K. We estimate that the noise contribution from the mixer is 500 K and the total losses are —15 dB at 137 MHz.
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	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
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	Notes				Approved	no
	Call Number				Serial	1626
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	Author	Gol'tsman, G. N.; Karasik, B. S.; Svechnikov, S. I.; Gershenzon, E. M.; Ekström, H.; Kollberg E.
	Title	Noise temperature of NbN hot—electron quasioptical superconducting mixer in 200-700 GHz range			Type	Abstract
	Year	1995	Publication	Proc. 6^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 6^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	268
	Keywords	NbN HEB mixers, noise temperature
	Abstract	The electron heating effect in superconducting films is becoming very attractive for the development of THz range mixers because of the absence of frequency limitations inherent in the bolometric mechanism. However, the evidence for the spectral dependence of the position of optimal operating point has been found recently for NbN thin film devices 1.2 • The effect is presumably attributed to the variation in the absorption of radiation depending on the frequency. Since the resistive state is not spatially uniform the coupling efficiency of the mixer device with radiation can be different for frequencies larger than Zeilh and those smaller than 2Alh (d is the effective superconducting gap in the resistive state). To study the effect more thoroughly we have investigated the noise temperature of quasioptical NbN mixer device with broken hue tapered slot antenna in the frequency range 200-700 GHz. The device consists of several (5-10) parallel strips 1 jim wide and 6-7 tun thick made from NbN film on Si0 2 -Si 3 N 4 -Si membrane. The strips are connected with the gold contacts of the slot-line antenna which serves both as bias and IF leads. We used backward wave oscillators as LO sources and a standard hot/cold load technique for noise temperature measurements. The frequency dependence of noise temperature is mainly determined by two factors: frequency properties of the antenna and frequency dependence of the NbN film impedance. To separate both factors we monitored the frequency dependence of the device responsivity in the detector mode at a higher temperature within the superconducting transition where the impedance of NbN film is close to its normal resistance. In this case the impedance of the device itself is frequency independent. The experimental results will be reported at the Symposium. 1. G. Gollsman, S. Jacobsson, H. EkstrOm, B. Karasik, E. Kollberg, and E. Gershenzon, “Slot-line tapered antenna with NbN hot electron mixer for 300-360 GHz operation,” Proc of the 5th Int. Symp. on Space Terahertz Technology, pp. 209-213a, May 10-12,1994. 2. B.S. Karasik, G.N. Gol i tsman, B.M. Voronov, S.I. Svechnikov, E.M. Gershenzon, H. Ekstrom, S. Jacobsson, E. Kollberg, and K.S. Yngvesson, “Hot electron quasioptical NbN superconducting mixer,” presented at the ASC94, submitted to IEEE Trans. on Appl. Superconductivity.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
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	Notes				Approved	no
	Call Number				Serial	1627
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	Author	Ekström, H.; Karasik, B.; Kollberg, E.; Gol'tsman, G.; Gershenzon, E.
	Title	350 GHz NbN hot electron bolometer mixer			Type	Conference Article
	Year	1995	Publication	Proc. 6^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 6^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	269-283
	Keywords	NbN HEB mixers
	Abstract	Superconducting NbN hot-electron bolometer (HEB) mixer devices have been fabricated and measured at 350 GHz. The HEB is integrated with a double dipole antenna on an extended crystalline quartz hyper hemispherical substrate lens. Heterodyne measurement gave a -3 dB bandwidth, mainly determined by the electron- phonon interaction time, of about 680 and 1000 MHz for two different films with Tc = 8.5 and 11 K respectively. The measured DSB receiver noise temperature is around 3000 K at 800 MHz IF frequency. The main contribution to the output noise from the device is due to electron temperature fluctuations with the equivalent output noise temperature TFL-100 K. TH, has the same frequency dependence as the IF response. The contribution from Johnson noise is of the order of T. The RF coupling loss is estimated to be = 6 dB. The film with lower Tc, had an estimated intrinsic low-frequency conversion loss = 7 dB, while the other film had a conversion loss as high as 14 dB. The difference in intrinsic conversion loss is explained by less uniform absorption of radiation. Measurements of the small signal impedance shows a transition of the output impedance from the DC differential resistance Rd=dV/dI in the low frequency limit to the DC resistance R 0 =Uoff 0 in the bias point for frequencies above 3 GHz. We judge that the optimum shape of the IV-characteristic is more easily obtained at THz frequencies where the main restriction in performance should come from problems with the RF coupling.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
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	Notes				Approved	no
	Call Number				Serial	1628
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	Author	Gerecht, E.; Musante, C. F.; Schuch, R.; Lutz, C. R.; Jr.; Yngvesson, K. S.; Mueller, E. R.; Waldivian, J.; Gol'tsman, G. N.; Voronov, B. M.; Gershenzon, E. M.
	Title	Hot electron detection and mixing experiments in NbN at 119 micrometer wavelength			Type	Conference Article
	Year	1995	Publication	Proc. 6^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 6^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	284-293
	Keywords	NbN HEB mixers, detectors
	Abstract	We have performed preliminary experiments with the goal of demonstrating a Hot Electron Bolometric (HEB) mixer for a 119 micrometer wavelength (2.5 THz). We have chosen a NbN device of size 700 x 350 micrometers. This device can easily be coupled to a laser LO source, which is advantageous for performing a prototype experiment. The relatively large size of the device means that the LO power required is in the mW range; this power can be easily obtained from a THz laser source. We have measured the amount of laser power actually absorbed in the device, and from this have estimated the best optical coupling loss to be about 10 di . We are developing methods for improving the optical coupling further. Preliminary measurements of the response of the device to a chopped black-body have not yet resulted in a measured receiver noise temperature. We expect to be able to complete this measurement in the near future.
	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
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	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1629
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	Author	Gol'tsman, G.; Jacobsson, S.; Ekstrom, H.; Karasik, B.; Kollberg, E.; Gershenzon, E.
	Title	Slot-line tapered antenna with NbN hot electron mixer for 300-360 GHz operation			Type	Conference Article
	Year	1994	Publication	Proc. 5^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 5^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	209-213a
	Keywords	NbN HEB mixers
	Abstract	NbN hot-electron mixers combined with slot-line tapered antennas on Si wdnitride membranes had been fabricated. Several strips of 1 gm wide and 5 tan long made from 100 A NbN film are inserted into the slot antenna. IV-curves under local oscillator power in 300-350 GHz frequency range and conversion gain dependencies on intermediate fre- quency in the 0.1-1 GHz range are measured and compared with that for 100 GHz frequency band. Our results show that pumped IV-curves and intermediate frequency bands are different for 100 GHz and 300 GHz frequency ranges. The interpretation exploits the fact that for the lowest radiation frequency the superconducting energy gap is larger than the radiation quantum energy while they are comparable at the higher frequency. Tha results show that such mixers have good perspectives for terahertz receiving technology.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
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	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1643
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	Author	0kunev, 0.; Dzardanov, A.; Ekstrom, H.; Jacobsson, S.; Kollberg, E.; Gol'tsman, G.; Gershenzon, E.
	Title	NbN hot electron waveguide mixer for 100 GHz operation			Type	Conference Article
	Year	1994	Publication	Proc. 5^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 5^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	214-224
	Keywords	waveguide NbN HEB mixers
	Abstract	NbN is a promising superconducting material used to develope hot- electron superconducting mixers with an IF bandwidth over 1 GHz. In the 100 GHz frequency range, the following parameters were obtained for NbN films 50 A thick: the noise temperature of the receiver (DSB) 1000 K; the conversion losses 10 d13, the IF bandwidth 1 GHz; the local oscillator power 1 /LW. An increase of NbN film thickness up to 80-100 A and increase of working temperature up to 7-8 K, and a better mixer matching may allow to broader the IF band up to 3 Gllz, to reduce the conversion losses down to 3-5 dB and the noise tempera- ture down to 200-300 K.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
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	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1644
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	Author	Gershenzon, E. M.; Gol'tsman, G. N.
	Title	Hot electron superconductive mixers			Type	Conference Article
	Year	1993	Publication	Proc. 4^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 4^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	618-622
	Keywords	HEB mixers
	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
	Notes				Approved	no
	Call Number				Serial	1656
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	Author	Gol'tsman, G. N.; Elant'iev, A. I.; Karasik, B. S.; Gershenzon, E. M.
	Title	Antenna – coupled superconducting electron-heating bolometer			Type	Conference Article
	Year	1993	Publication	Proc. 4^th Int. Symp. Space Terahertz Technol.	Abbreviated Journal	Proc. 4^th Int. Symp. Space Terahertz Technol.
	Volume		Issue		Pages	623-628
	Keywords	HEB
	Abstract	We propose a novel antenna-coupled superconducting bolometer based on electron-heating in the resistive state. A short narrow ultrathin super- conducting film strip (sized approximately 4x1x0.01 pm 3 ), which is in good thermal contact with the thermostat, serves as a resistive load for infrared or submillimeter current. In contrast to conventional isothermal super- conducting bolometers electron-heating ones can have a higher sensitivity which grows when filni. thickness is reduced. Response time of electron- heating bolometer does not depend on heat transfer from the film to the enviroment. To calculate the sensitivity (NEP), we have used experimental data on wideband Al, Nb and NbN bolometers which have the same un- derlying physical mechanism. The bolom.eters have been made in the form of a structure composed of a number of long narrow strips. The values of for Al, NEP have been found to be 1.5 . 113 -16 1 140 -15 ) and 2 . 10 – 14werT,-1/2 – Nb and NbN respectively. In the paper, the prospects are also discussed of improving the picosecond YBaCuO detector, developed recently. NEP value of the detector, if combined with a microantenna, can reach the order of 10- •ilz-v2.
	Address
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	Notes				Approved	no
	Call Number				Serial	1657
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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
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	Notes				Approved	no
	Call Number				Serial	1481
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	Author	Semenov, A.; Engel, A.; Il'in, K.; Gol'tsman, G.; Siegel, M.; Hübers, H.-W.
	Title	Ultimate performance of a superconducting quantum detector			Type	Journal Article
	Year	2003	Publication	Eur. Phys. J. Appl. Phys.	Abbreviated Journal	Eur. Phys. J. Appl. Phys.
	Volume	21	Issue	3	Pages	171-178
	Keywords	NbN SSPD, SNSPD
	Abstract	We analyze the ultimate performance of a superconducting quantum detector in order to meet requirements for applications in near-infrared astronomy and X-ray spectroscopy. The detector exploits a combined detection mechanism, in which avalanche quasiparticle multiplication and the supercurrent jointly produce a voltage response to a single absorbed photon via successive formation of a photon-induced and a current-induced normal hotspot in a narrow superconducting strip. The response time of the detector should increase with the photon energy providing energy resolution. Depending on the superconducting material and operation conditions, the cut-off wavelength for the single-photon detection regime varies from infrared waves to visible light. We simulated the performance of the background-limited infrared direct detector and X-ray photon counter utilizing the above mechanism. Low dark count rate and intrinsic low-frequency cut-off allow for realizing a background limited noise equivalent power of 10−20 W Hz−1/2 for a far-infrared direct detector exposed to 4-K background radiation. At low temperatures, the intrinsic response time of the counter is rather determined by diffusion of nonequilibrium electrons than by the rate of energy transfer to phonons. Therefore, thermal fluctuations do not hamper energy resolution of the X-ray photon counter that should be better than 10−3 for 6-keV photons. Comparison of new data obtained with a Nb based detector and previously reported results on NbN quantum detectors support our estimates of ultimate detector performance.
	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	1286-0042	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	534
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	Author	Aksaev, E. E.; Gershenzon, E.M.; Gol'tsman, G. N.; Mirskij, G. I.; Semenov, A. D.
	Title	Submillimetric spectrometer-relaxometer based on backward-wave tubes with picosecond time resolution			Type	Journal Article
	Year	1991	Publication	Pribory i Tekhnika Eksperimenta	Abbreviated Journal	Pribory i Tekhnika Eksperimenta
	Volume	34	Issue	2	Pages	125-131
	Keywords	BWO, applications
	Abstract	The high-sensitive automatic spectrometer-relaxometer based on backward-wave tubes in the range of 4÷0.25 mm was described permitting to study the response kinetics of sample under investigation in any point of this range with the resolution time of 10-11 s. The relaxation measurements were conducted using oscillation beats of two adequate tubes, the frequency of one of them was fixed, while that of the other one was changeable. The amplitude-frequency characteristic of the response under the conditions of synchronous reception was recorded at beat frequency variation from 107 to 1010 Hz. The high sensitivity was reached by decreasing the device recording band down to 100 Hz in the whole measuring 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	0032-8162	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1683
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	Author	Verevkin, A.; Gershenzon, E. M.; Gol'tsman, G. N.; Ptitsina, N. G.; Chulkova, G. M.; Smirnov, K. S.; Sobolewski, R.
	Title	Direct measurements of energy relaxation times in two-dimensional structures under quasi-equilibrium conditions			Type	Conference Article
	Year	2002	Publication	Mater. Sci. Forum	Abbreviated Journal	Mater. Sci. Forum
	Volume	384-3	Issue		Pages	107-116
	Keywords	2DEG, AlGaAs/GaAs
	Abstract	A new microwave technique was successfully applied for direct studies of energy relaxation times in two-dimensional AlGaAs/GaAs structures under quasi-equilibrium conditions in the nanosecond and picosecond time scale. We report our results of energy relaxation time measurements in the temperature range 1.6-50 K, in quantum Hall effect regime in magnetic fields up to 4 T.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
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	Area		Expedition		Conference	Materials Science Forum
	Notes				Approved	no
	Call Number				Serial	1536
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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
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	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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	Author	Karasik, B. S.; Il'in, K. S.; Ptitsina, N. G.; Gol'tsman, G. N.; Gershenzon, E. M.; Pechen', E. V.; Krasnosvobodtsev, S. I.
	Title	Electron-phonon scattering rate in impure NbC films			Type	Abstract
	Year	1998	Publication	NASA/ADS	Abbreviated Journal	NASA/ADS
	Volume		Issue		Pages	Y35.08
	Keywords	NbC films
	Abstract	The study of the electron-phonon interaction in thin (20 nm) NbC films with electron mean free path l=2-13 nm gives an evidence that electron scattering is significantly modified due to the interference between electron-phonon and elastic electron scattering from impurities. The interference ~T^2-term, which is proportional to the residual resistivity, dominates over the Bloch-Grüneisen contribution to resistivity at low temperatures up to 60 K. The electron energy relaxation rate is directly measured via the relaxation of hot electrons heated by modulated electromagnetic radiation. In the temperature range 1.5 – 10 K the relaxation rate shows a weak dependence on the electron mean free path and strong temperature dependence T^n with the exponent n = 2.5-3. This behaviour is well explained by the theory of the electron-phonon-impurity interference taking into account the electron coupling with transverse phonons determined from the resistivity data.
	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
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	Area		Expedition		Conference	American Physical Society, Annual March Meeting, March 16-20, 1998 Los Angeles, CA
	Notes				Approved	no
	Call Number				Serial	1591
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	Author	Gershenzon, E. M.; Gol'tsman, G. N.
	Title	Effect of electromagnetic radiation on a superconductor in a magnetic field			Type	Conference Article
	Year	1988	Publication	Izv. Akad. Nauk SSSR, Seriya Fizicheskaya	Abbreviated Journal	Izv. Akad. Nauk SSSR, Seriya Fizicheskaya
	Volume	52	Issue	3	Pages	449-451
	Keywords
	Abstract	The effect of electromagnetic radiation on thin superconducting films of Nb with a large number of static defects is investigated experimentally for the case where the film is in the resistive state due to an applied magnetic field and transport current. The results obtained are found to be well described by a model of spatially homogeneous electron heating. It is noted that the results obtained here for Nb films are also valid for Al, NbN, and MoRe films.
	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	0367-6765	ISBN		Medium
	Area		Expedition		Conference	4th Vsesoiuznyi Seminar po Opticheskomu Detektirovaniiu Magnitnykh Rezonansov v Tverdykh Telakh, Tallin, Estonian SSR, Apr. 1987
	Notes				Approved	no
	Call Number				Serial	1702
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	Author	Gershenson, E. M.; Gol'tsman, G. N.; Elant'ev, A. I.; Kagane, M. L.; Multanovskii, V. V.; Ptitsina, N. G.
	Title	Use of submillimeter backward-wave tube spectroscopy in determination of the chemical nature and concentration of residual impurities in pure semiconductors			Type	Journal Article
	Year	1983	Publication	Sov. Phys. Semicond.	Abbreviated Journal	Sov. Phys. Semicond.
	Volume	17	Issue	8	Pages	908-913
	Keywords	BWO spectroscopy, pure semiconductors, residual impurities
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
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	Notes	Применение субмиллиметровой ЛОВ спектроскопии для определения химической природы и концентрации примесей в чистых полупроводниках			Approved	no
	Call Number				Serial	1714
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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	Boyarskii, D. A.; Gershenzon, V. E.; Gershenzon, E. M.; Gol'tsman, G. N.; Ptitsina, N. G.; Tikhonov, V. V.; Chulkova, G. M.
	Title	On the possibility of determining the microstructural parameters of an oil-bearing layer from radiophysical measurement data			Type	Journal Article
	Year	1996	Publication	J. of Communications Technology and Electronics	Abbreviated Journal	J. of Communications Technology and Electronics
	Volume	41	Issue	5	Pages	408-414
	Keywords	submillimeter waves, transmission
	Abstract	A method for the reconstruction of microstructural properties of an oil-bearing rock from the spectral dependence of the transmission factor of submillimeter waves is proposed.
	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	1064-2269	ISBN		Medium
	Area		Expedition		Conference
	Notes	Радиотехника и электроника 41, no. 4 (1996): 441-447			Approved	no
	Call Number				Serial	1611
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	Author	Kitaygorsky, Jennifer; Komissarov, I.; Jukna, A.; Minaeva, O.; Kaurova, N.; Divochiy, A.; Korneev, A.; Tarkhov, M.; Voronov, B.; Milostnaya, I.; Gol'tsman, G.; Sobolewski, R.
	Title	Fluctuations in two-dimensional superconducting NbN nanobridges and nanostructures meanders			Type	Abstract
	Year	2007	Publication	Proc. APS March Meeting	Abbreviated Journal	Proc. APS March Meeting
	Volume	52	Issue	1	Pages	L9.00013
	Keywords
	Abstract	We have observed fluctuations, manifested as sub-nanosecond to nanosecond transient, millivolt-amplitude voltage pulses, generated in two-dimensional NbN nanobridges, as well as in extended superconducting meander nanostructures, designed for single photon counting. Both nanobridges and nano-stripe meanders were biased at currents close to the critical current and measured in a range of temperatures from 1.5 to 8 K. During the tests, the devices were blocked from all incoming radiation by a metallic enclosure and shielded from any external magnetic fields. We attribute the observed spontaneous voltage pulses to the Kosterlitz-Thouless-type fluctuations, where the high enough applied bias current reduces the binding energy of vortex-antivortex pairs and, subsequently, thermal fluctuations break them apart causing the order parameter to momentarily reduce to zero, which in turn causes a transient voltage pulse. The duration of the voltage pulses depended on the device geometry (with the high-kinetic inductance meander structures having longer, nanosecond, pulses) while their rate was directly related to the biasing current as well as 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	1027
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	Author	Gol'tsman, G. N.
	Title	Hot electron bolometric mixers: new terahertz technology			Type	Journal Article
	Year	1999	Publication	Infrared Physics & Technology	Abbreviated Journal	Infrared Physics & Technology
	Volume	40	Issue	3	Pages	199-206
	Keywords	NbN HEB mixers
	Abstract	This paper presents an overview of recent results for NbN phonon-cooled hot electron bolometric (HEB) mixers. The noise temperature of the receivers based on both quasioptical and waveguide versions of HEB mixers has crossed the level of 1 K GHz−1 at 430 GHz (410 K), 600–650 GHz (480 K), 750 GHz (600 K), 810 GHz (780 K) and is close to that level at 1.1 THz (1250 K) and 2.5 THz (4500 K). The gain bandwidth measured for quasioptical HEB mixer at 620 GHz reached 4 GHz and the noise temperature bandwidth was almost 8 GHz. Local oscillator power requirements are about 1 μW for mixers made by photolithography and about 100 nW for mixers made by e-beam lithography. A waveguide version of 800 GHz receiver was installed at the Submillimeter Telescope Observatory on Mt. Graham, AZ, to conduct astronomical observations of known submillimeter lines (CO, J=7→6, CI, J=2→1). It was proved that the receiver works as a practical instrument.
	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	1350-4495	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1570
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	Author	Lindgren, M.; Currie, M.; Zeng, W.-S.; Sobolewski, R.; Cherednichenko, S.; Voronov, B.; Gol'tsman, G. N.
	Title	Picosecond response of a superconducting hot-electron NbN photodetector			Type	Journal Article
	Year	1998	Publication	Appl. Supercond.	Abbreviated Journal	Appl. Supercond.
	Volume	6	Issue	7-9	Pages	423-428
	Keywords	NbN SSPD, SNSPD
	Abstract	The ps optical response of ultrathin NbN photodetectors has been studied by electro-optic sampling. The detectors were fabricated by patterning ultrathin (3.5 nm thick) NbN films deposited on sapphire by reactive magnetron sputtering into either a 5×10 μm2 microbridge or 25 1 μm wide, 5 μm long strips connected in parallel. Both structures were placed at the center of a 4 mm long coplanar waveguide covered with Ti/Au. The photoresponse was studied at temperatures ranging from 2.15 K to 10 K, with the samples biased in the resistive (switched) state and illuminated with 100 fs wide laser pulses at 395 nm wavelength. At T=2.15 K, we obtained an approximately 100 ps wide transient, which corresponds to a NbN detector response time of 45 ps. The photoresponse can be attributed to the nonequilibrium electron heating effect, where the incident radiation increases the temperature of the electron subsystem, while the phonons act as the heat sink. The high-speed response of NbN devices makes them an excellent choice for an optoelectronic interface for superconducting digital circuits, as well as mixers for the terahertz regime. The multiple-strip detector showed a linear dependence on input optical power and a responsivity =3.9 V/W.
	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	0964-1807	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1584
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	Author	Semenov, A. D.; Hübers, H.-W.; Richter, H.; Birk, M.; Krocka, M.; Mair, U.; Smirnov, K.; Gol'tsman, G. N.; Voronov, B. M.
	Title	2.5 THz heterodyne receiver with NbN hot-electron-bolometer mixer			Type	Journal Article
	Year	2002	Publication	Phys. C: Supercond.	Abbreviated Journal	Phys. C: Supercond.
	Volume	372-376	Issue		Pages	448-453
	Keywords	NbN HEB mixers, applications
	Abstract	We describe a 2.5 THz heterodyne receiver for applications in astronomy and atmospheric research. The receiver employs a superconducting NbN phonon-cooled hot-electron-bolometer mixer and an optically pumped far-infrared gas laser as local oscillator. 2200 K double sideband mixer noise temperature was measured at 2.5 THz across a 1 GHz intermediate frequency bandwidth centred at 1.5 GHz. The total conversion losses were 17 dB. The mixer response was linear at load temperatures smaller than 400 K. The receiver was tested in the laboratory environment by measuring the methanol line in emission. Observed pressure broadening confirms the true heterodyne detection regime of the 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	0921-4534	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1526
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	Author	Cherednichenko, S.; Kroug, M.; Merkel, H.; Khosropanah, P.; Adam, A.; Kollberg, E.; Loudkov, D.; Gol'tsman, G.; Voronov, B.; Richter, H.; Huebers, H.-W.
	Title	1.6 THz heterodyne receiver for the far infrared space telescope			Type	Journal Article
	Year	2002	Publication	Phys. C: Supercond.	Abbreviated Journal	Phys. C: Supercond.
	Volume	372-376	Issue		Pages	427-431
	Keywords	NbN HEB mixers, applications
	Abstract	A low noise heterodyne receiver is being developed for the terahertz range using a phonon-cooled hot-electron bolometric mixer based on 3.5 nm thick superconducting NbN film. In the 1–2 GHz intermediate frequency band the double-sideband receiver noise temperature was 450 K at 0.6 THz, 700 K at 1.6 THz and 1100 K at 2.5 THz. In the 3–8 GHz IF band the lowest receiver noise temperature was 700 K at 0.6 THz, 1500 K at 1.6 THz and 3000 K at 2.5 THz while it increased by a factor of 3 towards 8 GHz.
	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	0921-4534	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1527
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	Author	Cherednichenko, S.; Rönnung, F.; Gol'tsman, G.; Kollberg, E.; Winkler, D.
	Title	YBa2Cu3O7−δ hot-electron bolometer mixer			Type	Journal Article
	Year	2000	Publication	Phys. C: Supercond.	Abbreviated Journal	Phys. C: Supercond.
	Volume	341-348	Issue		Pages	2653-2654
	Keywords	YBCO HTS HEB mixers
	Abstract	We present an investigation of hot-electron bolometric mixer based on YBa2Cu3O7−δ (YBCO) superconducting thin film. Mixer conversion loss, absorbed local oscillator power and intermediate frequency bandwidth was measured at the local oscillator frequency 600 GHz. The fabrication technique for nanoscale YBCO hot-electron bolometer (HEB) mixer integrated into planar antenna structure is described.
	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	0921-4534	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1552
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	Author	Varyukhin, S. V.; Zakharov, A. A.; Gershenzon, E. M.; Gol'tsman, G. N.; Ptitsyna, N. G.; Chulkova, G. M.
	Title	AC losses and submillimeter absorption in single crystals La2CuO4			Type	Journal Article
	Year	1990	Publication	Phys. B Condens. Mat.	Abbreviated Journal	Phys. B Condens. Mat.
	Volume	165-166	Issue		Pages	1269-1270
	Keywords	metal-dielectric-La2Cu04
	Abstract	The La2CuO4 single crystals were used to carry out the measurements of transmission spectra within the submillimeter range of wavelengths, as well as the capacitance C and conductivity G in the region of acoustic frequencies of the metal-dielectric-La2Cu04 system at low temperatures. The optical spectra display a threshold character. There takes place a sharp decreasing of transmission signal in the energy range of hυ>1.5meV. The C(ω,T) and G(ω,T) dependences have a universal form characteristic of relaxation processes of the Debye type. The relaxation time dependence displays a thermoactivation character τ(T)-exp(ξ/T) with a gap value of ξ≃2meV,coinciding with the optical one. It is assumed that there exist excitations with a characteristic energy ~ 2meV in La2Cu04.A possible nature of the revealed low-energy excitations 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	0921-4526	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1686
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	Author	Karasik, B.S.; Milostnaya, I.I.; Zorin, M.A.; Elantev, A.I.; Gol'tsman, G.N.; Gershenzon, E.M.
	Title	Subnanosecond S-N and N-S switching of YBCO film induced by current pulse			Type	Journal Article
	Year	1994	Publication	Phys. C: Supercond.	Abbreviated Journal	Phys. C: Supercond.
	Volume	235-240	Issue		Pages	1981-1982
	Keywords	YBCO HTS switches
	Abstract	A transition of YBCO bridge 60 nm thick from superconducting to normal state induced by an abrupt current step has been studied. A subnanosecond stage has been observed during both S-N and N-S transition. The data obtained can be explained by hot-electron phenomena. On the basis of experimental results a prediction of picosecond switch performance has been made.
	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	0921-4534	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1633
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	Author	Gol'tsman, G. N.; Kouminov, P.; Goghidze, I.; Gershenzon, E. M.
	Title	Nonequilibrium kinetic inductive response of YBaCuO thin films to low-power laser pulses			Type	Journal Article
	Year	1994	Publication	Phys. C: Supercond.	Abbreviated Journal	Phys. C: Supercond.
	Volume	235-240	Issue		Pages	1979-1980
	Keywords	YBCO HTS KID
	Abstract	Transient non-equilibrium kinetic inductive voltage response of YBaCuO thin films to 20 ps pulses of YAG:Nd laser radiation with 0.63 μm and 1.5 μm wavelength has been revealed. By increasing the sensitivity of 100 ps resolution time registration system and diminishing light intensity (fluence 0.1-1 μJ2/cm2) and transport current (density j≤105 A/cm2) we observed a perculiar bipolar signal form with nearly equal amplitudes of each sign. The integration of the kinetic inductive response over time gives the result which is qualitatively of the same form as the response in the resistive and normal states: nonequilibrium picosecond scale component followed by bolometric nanosecond. Nonequilibrium response is interpreted as suppression of order parameter by excess of quasiparticles followed by a change in resistance in the resistive state and kinetic inductance in superconductive state.
	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	0921-4534	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1634
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	Author	Gershenzon, E. M.; Gol'tsman, G. N.; Gogidze, I. G.; Semenov, A. D.; Sergeev, A. V.
	Title	Processes of electron-phonon interaction in thin YBaCuO films			Type	Journal Article
	Year	1991	Publication	Phys. C: Supercond.	Abbreviated Journal	Phys. C: Supercond.
	Volume	185-189	Issue		Pages	1371-1372
	Keywords	YBCO HTS detectors
	Abstract	The ultrafast voltage response of YBaCuO films to laser radiation is studied and compared with previously investigated quasiparicles response to radiation of submillimeter wavelength range. Voltage shift under the visible light radiation has two components. Picosecond response realized as suppression superconductivity by nonequilibrium excess quasiparticles, response time is determined by quasiparticles recombination rate. Nanosecond response is probably due to bolometric effect.
	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	0921-4534	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1676
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	Author	Gousev, Y. P.; Semenov, A. D.; Gol'tsman, G. N.; Sergeev, A. V.; Gershenzon, E. M.
	Title	Electron-phonon interaction in disordered NbN films			Type	Journal Article
	Year	1994	Publication	Phys. B Condens. Mat.	Abbreviated Journal	Phys. B Condens. Mat.
	Volume	194-196	Issue		Pages	1355-1356
	Keywords	NbN films
	Abstract	Electron-phonon interaction time has been investigated in disordered films of NbN. A temperatures below 5.5 K tau_eph ~ T -1"6 which is attributed to the renormalisation of phonon spectrum in thin 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	0921-4526	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1649
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	Author	Gershenzon, E. M.; Gol'tsman, G. N.; Potapov, V. D.; Sergeev, A. V.
	Title	Restriction of microwave enhancement of superconductivity in impure superconductors due to electron-electron interaction			Type	Journal Article
	Year	1991	Publication	Phys. B Condens. Mat.	Abbreviated Journal	Phys. B Condens. Mat.
	Volume	169	Issue	1-4	Pages	629-630
	Keywords	impure superconductors
	Abstract	Transition from microwave enhancement of supercurrent to superconductivity suppression is investigated in impure superconductors. It is demonstrated that frequency range of enhancement effect narrows with the decrease of electron mean free path, ℓ, and at ℓ⩽1nm electron heating is observed in the whole frequency range. Dependences of frequency boundaries on ℓ are explained by taking into account strong electron-electron interaction in impure metals.
	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	0921-4526	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1682
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	Author	Verevkin, A. A.; Ptitsina, N. G.; Chulcova, G. M.; Gol'tsman, G. N.; Gershenzon, E. M.; Yngvesson, K. S.
	Title	Direct measurements of energy relaxation time of electrons in AlGaAs/GaAs heterostructures under quasi-equilibrium conditions			Type	Journal Article
	Year	1996	Publication	Surface Science	Abbreviated Journal	Surface Science
	Volume	361-362	Issue		Pages	569-573
	Keywords	2DEG, AlGaAs/GaAs heterostructures
	Abstract	For the first time, results are presented of a direct measurement of the energy relaxation time τε of 2D electrons in an AlGaAs/GaAs heterojunction at T = 1 and 5–20 K. A weak temperature dependence of τε for the T > 4K range and a linear temperature dependence of the reciprocal of τε for T < 4K have been observed. The linear dependence τε−1 ≈ T in the Bloch-Gruneisen regime is direct evidence of the predominance of the piezo-electric mechanism of electron-phonon interaction in non-elastic electron scattering processes. The values of τε in this regime are in very good agreement with the results of the Karpus theory. At higher temperatures, where the deformation-potential scattering becomes noticeable, a substantial disagreement between the experimental data and the theoretical results is 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	0039-6028	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1609
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	Author	Bespalov, A.V.; Gol'tsman, G.N.; Semenov, A.D.; Renk, K.F.
	Title	Determination of the far-infrared emission characteristic of a cyclotron p-germanium laser by use of a superconducting Nb detector			Type	Journal Article
	Year	1991	Publication	Solid State Communications	Abbreviated Journal	Solid State Communications
	Volume	80	Issue	7	Pages	503-506
	Keywords	Nb detector, applications
	Abstract	We studied the far-infrared emission characteristics of a cyclotron p-germanium laser using a broad-band superconducting Nb film detector. For magnetic fields between ∼25 kOe and ∼50 kOe, emission in a frequency range from ∼50 cm-1 to ∼100 cm-1 with maximum intensity around 90 cm-1 was obtained. We determined, for fixed magnetic fields, electric field dependences of the emission intensity taking into account that the total electric field is a sum of the applied and the Hall electric field. An analysis of the emission intensity characteristic gives evidence that transitions between the two lowest Landau levels of light holes are responsible for the laser action.
	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	0038-1098	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1677
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	Author	Gershenzon, E. M.; Gol'tsman, G. N.; Semenov, A. D.; Sergeev, A. V.
	Title	Mechanism of picosecond response of granular YBaCuO films to electromagnetic radiation			Type	Journal Article
	Year	1990	Publication	Solid State Communications	Abbreviated Journal	Solid State Communications
	Volume	76	Issue	4	Pages	493-497
	Keywords	YBCO HTS detectors
	Abstract	The ultrafast mechanisms of radiation detection in granular YBaCuO films are studied in the wide wavelength range from millimeter to near infrared. With the rise of radiation frequency the Josephson detection at the grain boundary weak links is replaced by electron heating into the grains. This change occurs in the submillimeter wavelength range. Electron-phonon relaxation time τeph is determined by direct measurements and analyses quasistationary electron heating. Temperature dependence of τeph at T ≤ 40 K was found to be τeph ∼ T−1. The results show that detectors with the response time of few picoseconds at nitrogen temperature are attainable.
	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	0038-1098	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1685
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	Author	Gershenzon, E. M.; Gol'tsman, G. N.; Potapov, V. D.; Sergeev, A. V.
	Title	Restriction of microwave enhancement of superconductivity in impure superconductors due to electron-electron interaction			Type	Journal Article
	Year	1990	Publication	Solid State Communications	Abbreviated Journal	Solid State Communications
	Volume	75	Issue	8	Pages	639-641
	Keywords	impure superconductors
	Abstract	Transition from microwave enhancement of supercurrent to superconductivity suppression is investigated in impure superconductors. It is demonstrated that the frequency range of the enhancement effect narrows with the decrease of the electron mean free path, l, and at l ⩽ 1 nm electron heating is observed in the whole frequency range. Dependences of frequency boundaries on l are explained by taking into account strong electron-electron interaction in impure metals.
	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	0038-1098	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1687
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	Author	Gershenzon, E. M.; Gershenzon, M. E.; Gol'tsman, G. N.; Semyonov, A. D.; Sergeev, A. V.
	Title	Heating of electrons in superconductor in the resistive state due to electromagnetic radiation			Type	Journal Article
	Year	1984	Publication	Solid State Communications	Abbreviated Journal	Solid State Communications
	Volume	50	Issue	3	Pages	207-212
	Keywords	Nb HEB
	Abstract	The effect of heating electrons with respect to phonons in a thin superconducting film driven into the resistive state by the current and the external magnetic field has been observed and investigated. This effect caused by the electromagnetic radiation is manifested in the increased resistance of the film and is not selective over the frequency range from 1010 to 1015 Hz. That the effect is frequency independent under the conditions of strong electron scattering caused by static defects is explained by the decisive role of electron -electron collisions in forming the distribution function. The characteristic time of resistance change, obtained experimentally, corresponds to the relaxation time of the order parameter near the superconducting transition and to the relaxation time of the nonelastic electron-phonon interaction at lower temperatures and in lower magnetic fields.
	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	0038-1098	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1709
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	Author	Gol'tsman, G. N.; Loudkov, D. N.
	Title	Terahertz superconducting hot-electron bolometer mixers and their application in radio astronomy			Type	Journal Article
	Year	2003	Publication	Radiophys. Quant. Electron.	Abbreviated Journal
	Volume	46	Issue	8/9	Pages	604-617
	Keywords	NbN HEB mixers
	Abstract	We review the latest developments, research, and radioastronomy applications of hot-electron bolometer (HEB) mixers operated in the terahertz waveband. The physical principles of operation of terahertz HEB mixers are presented, their manufacturing from ultrathin NbN films, the main HEB-mixer parameters and their measurement techniques are discussed, and practical terahertz radioastronomy projects based on heterodyne receivers with HEB mixers are considered.
	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	0033-8443	ISBN		Medium
	Area		Expedition		Conference
	Notes	UDC 537.312.62			Approved	no
	Call Number				Serial	472
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	Author	Lusche, R.; Semenov, A.; Korneeva, Y.; Trifonov, A.; Korneev, A.; Gol'tsman, G.; Hübers, H.-W.
	Title	Effect of magnetic field on the photon detection in thin superconducting meander structures			Type	Journal Article
	Year	2014	Publication	Phys. Rev. B	Abbreviated Journal	Phys. Rev. B
	Volume	89	Issue	10	Pages	104513 (1 to 7)
	Keywords	NbN SSPD, SNSPD
	Abstract	We have studied the influence of an externally applied magnetic field on the photon and dark count rates of meander-type niobium nitride superconducting nanowire single-photon detectors. Measurements have been performed at a temperature of 4.2 K, and magnetic fields up to 250 mT have been applied perpendicularly to the meander plane. While photon count rates are field independent at weak applied fields, they show a strong dependence at fields starting from approximately ±25 mT. This behavior, as well as the magnetic field dependence of the dark count rates, is in good agreement with the recent theoretical model of vortex-assisted photon detection and spontaneous vortex crossing in narrow superconducting lines. However, the local reduction of the superconducting free energy due to photon absorption, which is the fitting parameter in the model, increases much slower with the photon energy than the model predicts. Furthermore, changes in the free-energy during photon counts and dark counts depend differently on the current that flows through the meander. This indicates that photon counts and dark counts occur in different parts of the meander.
	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	1367
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	Author	Korneev, A.; Divochiy, A.; Tarkhov, M.; Minaeva, O.; Seleznev, V.; Kaurova, N.; Voronov, B.; Okunev, O.; Chulkova, G.; Milostnaya, I.; Smirnov, K.; Gol'tsman, G.
	Title	New advanced generation of superconducting NbN-nanowire single-photon detectors capable of photon number resolving			Type	Conference Article
	Year	2008	Publication	J. Phys.: Conf. Ser.	Abbreviated Journal	J. Phys.: Conf. Ser.
	Volume	97	Issue		Pages	012307 (1 to 6)
	Keywords	PNR SSPD; SNSPD
	Abstract	We present our latest generation of ultrafast superconducting NbN single-photon detectors (SSPD) capable of photon-number resolving (PNR). We have developed, fabricated and tested a multi-sectional design of NbN nanowire structures. The novel SSPD structures consist of several meander sections connected in parallel, each having a resistor connected in series. The novel SSPDs combine 10 μm × 10 μm active areas with a low kinetic inductance and PNR capability. That resulted in a significantly reduced photoresponse pulse duration, allowing for GHz counting rates. The detector's response magnitude is directly proportional to the number of incident photons, which makes this feature easy to use. We present experimental data on the performances of the PNR SSPDs. The PNR SSPDs are perfectly suited for fibreless free-space telecommunications, as well as for ultrafast quantum cryptography and quantum computing.
	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	1742-6596	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	1245
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	Author	Casaburi, A.; Ejrnaes, M.; Quaranta, O.; Gaggero, A.; Mattioli, F.; Leoni, R.; Voronov, B.; Gol'tsman, G.; Lisitskiy, M.; Esposito, E.; Nappi, C.; Cristiano, R.; Pagano, S.
	Title	Experimental characterization of NbN nanowire optical detectors with parallel stripline configuration			Type	Conference Article
	Year	2008	Publication	J. Phys.: Conf. Ser.	Abbreviated Journal	J. Phys.: Conf. Ser.
	Volume	97	Issue		Pages	012265 (1 to 6)
	Keywords	NbN SSPD, SNSPD
	Abstract	We have developed a novel geometrical configuration for NbN-based superconducting single photon optical detector (SSPD) that achieves two goals: a much lower intrinsic impedance, and a consequently greater bandwidth, and a much larger signal amplitude compared to the standard meandered configuration. This has been obtained by implementing a properly designed parallel stripline structure where a cascade switching mechanism occurs when one of the striplines is hit by an optical photon. The overall switching occurs synchronously and in a very short time, giving rise to a strong and fast voltage pulse. The SSPD have been realized using state of the art NbN deposition technology and e-beam lithography. The strips are 100 nm wide and 5 μm long and have been realized with 4 nm NbN film on sapphire and Si substrate. We report on experimental characterization of such novel devices. The performances of the proposed novel type of SSPD are compared with standard SSPD design and results in terms of signal amplitude, risetime and effective detection area.
	Address
	Corporate Author				Thesis
	Publisher	IOP Publishing	Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1742-6596	ISBN		Medium
	Area		Expedition		Conference	8th European Conference on Applied Superconductivity (EUCAS 2007)
	Notes				Approved	no
	Call Number				Serial	1416
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	Author	Smirnov, K.; Korneev, A.; Minaeva, O.; Divochiy, A.; Tarkhov, M.; Ryabchun, S.; Seleznev, V.; Kaurova, N.; Voronov, B.; Gol'tsman, G.; Polonsky, S.
	Title	Ultrathin NbN film superconducting single-photon detector array			Type	Conference Article
	Year	2007	Publication	J. Phys.: Conf. Ser.	Abbreviated Journal	J. Phys.: Conf. Ser.
	Volume	61	Issue		Pages	1081-1085
	Keywords	SSPD array
	Abstract	We report on the fabrication process of the 2 × 2 superconducting single-photon detector (SSPD) array. The SSPD array is made from ultrathin NbN film and is operated at liquid helium temperatures. Each detector is a nanowire-based structure patterned by electron beam lithography process. The advances in fabrication technology allowed us to produce highly uniform strips and preserve superconducting properties of the unpatterned film. SSPD exhibit up to 30% quantum efficiency in near infrared and up to 1% at 5-μm wavelength. Due to 120 MHz counting rate and 18 ps jitter, the time-domain multiplexing read-out is proposed for large scale SSPD arrays. Single-pixel SSPD has already found a practical application in non-invasive testing of semiconductor very-large scale integrated circuits. The SSPD significantly outperformed traditional single-photon counting avalanche diodes.
	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	408
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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	Danerud, M.; Winkler, D.; Lindgren, M.; Zorin, M.; Trifonov, V.; Karasik, B.; Gershenzon, E. M.; Gol'tsman, G. N.
	Title	A fast infrared detector based on patterned YBCO thin film			Type	Journal Article
	Year	1994	Publication	Supercond. Sci. Technol.	Abbreviated Journal	Supercond. Sci. Technol.
	Volume	7	Issue	5	Pages	321-323
	Keywords	YBCO HTS detector
	Abstract	Detectors for infrared radiation ( lambda =0.85 mu m) were made of 50 nm thick YBa2Cu3O7- delta films on LaAlO3 and MgO or 60 nm thick films on NdGaO3. Parallel strips (1 mu m wide by 20 mu m long) were patterned in the films and formed the active device. These devices were designed to detect short infrared laser pulses by electron heating. The detectors were current biased into the resistive and the normal states. The response was studied in direct pulse measurements as well as by amplitude modulation of a laser. The pulse measurements showed a fast picosecond response followed by a slower decay related to phonon escape through the film-substrate interface and heat diffusion in the substrate. The frequency spectra up to 10 GHz showed two slopes with a knee corresponding to the phonon escape time.
	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	1646
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	Author	Gol'tsman, G. N.; Semenov, A. D.; Gousev, Y. P.; Zorin, M. A.; Gogidze, I. G.; Gershenzon, E. M.; Lang, P. T.; Knott, W. J.; Renk, K. F.
	Title	Sensitive picosecond NbN detector for radiation from millimetre wavelengths to visible light			Type	Journal Article
	Year	1991	Publication	Supercond. Sci. Technol.	Abbreviated Journal	Supercond. Sci. Technol.
	Volume	4	Issue	9	Pages	453-456
	Keywords	NbN HEB detectors
	Abstract	The authors report on the application of a broad-band NbN film detector which has high sensitivity and picosecond response time for detection of radiation from millimetre wavelengths to visible light. From a study of amplitude modulated radiation of backward-wave tubes and picosecond pulses from gas and solid state lasers at wavelengths between 2 mm and 0.53 mu m, they found a detectivity of 1010 W-1 cm Hz-1/2 and a response time of less than 50 ps at T=10 K. The characteristics were provided by using a 150 AA thick NbN film patterned into a structure of micron strips. According to the proposed detection mechanism, namely electron heating, they expect an intrinsic response time of approximately 20 ps at the same 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	0953-2048	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number				Serial	242
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	Author	Lipatov, A.; Okunev, O.; Smirnov, K.; Chulkova, G.; Korneev, A.; Kouminov, P.; Gol'tsman, G.; Zhang, J.; Slysz, W.; Verevkin, A.; Sobolewski, R.
	Title	An ultrafast NbN hot-electron single-photon detector for electronic applications			Type	Journal Article
	Year	2002	Publication	Supercond. Sci. Technol.	Abbreviated Journal	Supercond. Sci. Technol.
	Volume	15	Issue	12	Pages	1689-1692
	Keywords	NbN SSPD, SNSPD, QE, jitter, dark counts
	Abstract	We present the latest generation of our superconducting single-photon detector (SPD), which can work from ultraviolet to mid-infrared optical radiation wavelengths. The detector combines a high speed of operation and low jitter with high quantum efficiency (QE) and very low dark count level. The technology enhancement allows us to produce ultrathin (3.5 nm thick) structures that demonstrate QE hundreds of times better, at 1.55 μm, than previous 10 nm thick SPDs. The best, 10 × 10 μm2, SPDs demonstrate QE up to 5% at 1.55 μm and up to 11% at 0.86 μm. The intrinsic detector QE, normalized to the film absorption coefficient, reaches 100% at bias currents above 0.9 Ic for photons with wavelengths shorter than 1.3 μm.
	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	1533
Permanent link to this record



	Author	Rönnung, F.; Cherednichenko, S.; Winkler, D.; Gol'tsman, G. N.
	Title	A nanoscale YBCO mixer optically coupled with a bow tie antenna			Type	Journal Article
	Year	1999	Publication	Supercond. Sci. Technol.	Abbreviated Journal	Supercond. Sci. Technol.
	Volume	12	Issue	11	Pages	853-855
	Keywords	YBCO HTS HEB mixers
	Abstract	The bolometric response of YBa₂Cu₃O_7-δ(YBCO) hot-electron bolometers (HEBs) to near-infrared radiation was studied. Devices were fabricated from a 50 nm thick film and had in-plane areas of 10 × 10 µm2, 2 × 0.2 µm2, 1 × 0.2µm2 and 0.5 × 0.2 µm2. We found that nonequilibrium phonons cool down more effectively for the bolometers with smaller area. For the smallest bolometer the bolometric component in the response is 10 dB less than for the largest one.
	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	1563
Permanent link to this record



	Author	Il'in, K. S.; Verevkin, A. A.; Gol'tsman, G. N.; Sobolewski, R.
	Title	Infrared hot-electron NbN superconducting photodetectors for imaging applications			Type	Journal Article
	Year	1999	Publication	Supercond. Sci. Technol.	Abbreviated Journal	Supercond. Sci. Technol.
	Volume	12	Issue	11	Pages	755-758
	Keywords	NbN SSPD, SNSPD
	Abstract	We report an effective quantum efficiency of 340, responsivity >200 A W-1 (>104 V W-1) and response time of 27±5 ps at temperatures close to the superconducting transition for NbN superconducting hot-electron photodetectors (HEPs) in the near-infrared and optical ranges. Our studies were performed on a few nm thick NbN films deposited on sapphire substrates and patterned into µm-size multibridge detector structures, incorporated into a coplanar transmission line. The time-resolved photoresponse was studied by means of subpicosecond electro-optic sampling with 100 fs wide laser pulses. The quantum efficiency and responsivity studies of our photodetectors were conducted using an amplitude-modulated infrared beam, fibre-optically coupled to the device. The observed picosecond response time and the very high efficiency and sensitivity of the NbN HEPs make them an excellent choice for infrared imaging photodetectors and input optical-to-electrical transducers for superconducting digital circuits.
	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	1562
Permanent link to this record



	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
Permanent link to this record



	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
Permanent link to this record



	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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