Home << 1 2 3 4 5 6 7 >>
List View
 | 
Citations
 | 
Details
   web
Records
Author Cherednichenko, S.; Drakinskiy, V.; Baubert, J.; Lecomte, B.; Dauplay, F.; Krieg, J.-M.; Delorme, Y.; Feret, A.; Hübers, H.-W.; Semenov, A. D.; Gol’tsman, G. N.
Title (up) 2.5 THz multipixel heterodyne receiver based on NbN HEB mixers Type Abstract
Year 2007 Publication Proc. 18th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 18th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 112
Keywords NbN HEB mixers
Abstract A 16 pixel heterodyne receiver for 2.5 THz has been developed based on NbN superconducting hot-electron bolometer (HEB) mixers. The receiver uses a quasioptical RF coupling approach where HEB mixers are integrated into double dipole antennas on 1.5μm thick Si3N4 / SiO2 membranes. Spherical mirrors (one per pixel) and backshort distance from the antenna have been used to design the output mixer beam profile. The camera design allows all 16 pixel IF readout in parallel. Measurements of the mixers sensitivity and the input RF band are presented, and compared against calculations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1419
Permanent link to this record
 
 
Author Ejrnaes, M.; Cristiano, R.; Quaranta, O.; Pagano, S.; Gaggero, A.; Mattioli, F.; Leoni, R.; Voronov, B.; Gol’tsman, G.
Title (up) A cascade switching superconducting single photon detector Type Journal Article
Year 2007 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 91 Issue 26 Pages 262509 (1 to 3)
Keywords SSPD, SNSPD, parallel-wire
Abstract We have realized superconducting single photon detectors with reduced inductance and increased signal pulse amplitude. The detectors are based on a parallel connection of ultrathin NbN nanowires with a common bias inductance. When properly biased, an absorbed photon induces a cascade switch of all the parallel wires generating a signal pulse amplitude of 2mV. The parallel wire configuration lowers the detector inductance and reduces the response time well below 1ns.

This work was performed in the framework of the EU project “SINPHONIA” NMP4-CT-2005-016433.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1418
Permanent link to this record
 
 
Author
Title (up) Atacama large millimeter/submillimeter array Type
Year 2007 Publication Abbreviated Journal
Volume Issue Pages
Keywords
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ s @ ALMA_proj Serial 403
Permanent link to this record
 
 
Author Jiang, L.; Antipov, S. V.; Voronov, B. M.; Gol'tsman, G. N.; Zhang, W.; Li, N.; Lin, Z. H.; Yao, Q. J.; Miao, W.; Shi, S. C.; Svechnikov, S. I.; Vakhtomin, Y. B.
Title (up) Characterization of the performance of a quasi-optical NbN superconducting HEB mixer Type Journal Article
Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 17 Issue 2 Pages 395-398
Keywords NbN HEB mixers, noise temperature
Abstract In this paper we focus mainly on the investigation of the performance of a quasi-optical (planar log-spiral antenna) phonon-cooled NbN superconducting hot electron bolometer (HEB) mixer, which is cryogenically cooled by a close-cycled 4-K cryocooler, at 500 and 850 GHz frequency bands. The mixer's noise performance, stability of IF output power, and local oscillator (LO) power requirement are characterized for three NbN superconducting HEB devices of different sizes. The transmission characteristics of Mylar and Zitex films with incidence waves of an elliptical polarization are also examined by measuring the mixer's noise temperature. The lowest receiver noise temperatures (with no corrections) of 750 and 1100 K are measured at 500 and 850 GHz, respectively. Experimental results also demonstrate that the bigger the HEB device is, the higher the stability of IF output power becomes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1429
Permanent link to this record
 
 
Author Kopp, Victor I.; Churikov, Victor M.; Zhang, Guoyin; Singer, Jonathan; Draper, Christopher W.; Chao, Norman; Neugroschl, Daniel; Genack, Azriel Z.
Title (up) Chiral fiber gratings: perspectives and challenges for sensing applications Type Conference Article
Year 2007 Publication Proceedings of Third european workshop on optical fibre sensors Abbreviated Journal Proc. 3rd European Workshop on Opt. Fibre Sensors
Volume 6619 Issue Pages 66190B-(1-8)
Keywords optical fiber gratings, chiral fiber gratings applications, chiral gratings applications, from chiralphotonics
Abstract Chiral fiber gratings are produced in a microforming process in which optical fibers with noncircular or nonconcentric cores are twisted as they pass though a miniature oven. Periodic glass structures as stable as the glass material itself are produced with helical pitch that ranges from under a micron to hundreds of microns. The geometry of the fiber cross section determines the symmetry of the resulting structure which in turn determines its polarization selectivity. Single helix structures are polarization insensitive while double helix gratings interact only with a single optical polarization. Both single and double helix gratings may act as a fiber long period grating, coupling the core and cladding modes. The coupling is manifested in a series of narrow dips in the transmission spectrum. The dip position is sensitive to fiber elongation, twist and temperature, and to the refractive index of the surrounding medium. The suitability of chiral gratings for sensing pressure, temperature and liquid levels is investigated. Polarization insensitive single helix silica glass gratings display excellent stability up to temperatures of 6000C, while a pressure sensor with dynamic range of nearly 40 dB is demonstrated in polarization selective double helix gratings.
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 855
Permanent link to this record
 
 
Author Dickert, Franz L.
Title (up) Christoph A. Schalley (Ed.): Analytical methods in supramolecular chemistry Type Journal Article
Year 2007 Publication Analytical and Bioanalytical Chemistry Abbreviated Journal Anal Bioanal Chem
Volume 389 Issue 7-8 Pages 2039-2040
Keywords supramolecular recognition
Abstract This is a review of book.
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 1618-2642 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 563
Permanent link to this record
 
 
Author Kerman, A. J.; Dauler, E. A.; Yang, J. K. W.; Rosfjord, K. M.; Anant, V.; Berggren, K. K.; Gol’tsman, G. N.; Voronov, B. M.
Title (up) Constriction-limited detection efficiency of superconducting nanowire single-photon detectors Type Journal Article
Year 2007 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 90 Issue 10 Pages 101110 (1 to 3)
Keywords SSPD, SNSPD
Abstract We investigate the source of the large variations in the observed detection efficiencies of superconducting nanowire single-photon detectors between many nominally identical devices. Through both electrical and optical measurements, we infer that these variations arise from “constrictions:” highly localized regions of the nanowires where the effective cross-sectional area for superconducting current is reduced. These constrictions limit the bias-current density to well below its critical value over the remainder of the wire, and thus prevent the detection efficiency from reaching the high values that occur in these devices when they are biased near the critical current density.

This work is sponsored by the United States Air Force under Contract No. FA8721-05-C-0002.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1433
Permanent link to this record
 
 
Author Kitaygorsky, J.; Komissarov, I.; Jukna, A.; Pan, D.; Minaeva, O.; Kaurova, N.; Divochiy, A.; Korneev, A.; Tarkhov, M.; Voronov, B.; Milostnaya, I.; Gol'tsman, G.; Sobolewski, R.R.
Title (up) Dark counts in nanostructured nbn superconducting single-photon detectors and bridges Type Journal Article
Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 17 Issue 2 Pages 275-278
Keywords SSPD; SNSPD
Abstract We present our studies on dark counts, observed as transient voltage pulses, in current-biased NbN superconducting single-photon detectors (SSPDs), as well as in ultrathin (~4 nm), submicrometer-width (100 to 500 nm) NbN nanobridges. The duration of these spontaneous voltage pulses varied from 250 ps to 5 ns, depending on the device geometry, with the longest pulses observed in the large kinetic-inductance SSPD structures. Dark counts were measured while the devices were completely isolated (shielded by a metallic enclosure) from the outside world, in a temperature range between 1.5 and 6 K. Evidence shows that in our two-dimensional structures the dark counts are due to the depairing of vortex-antivortex pairs caused by the applied bias current. Our results shed some light on the vortex dynamics in 2D superconductors and, from the applied point of view, on intrinsic performance of nanostructured SSPDs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1248
Permanent link to this record
 
 
Author Semenov, A.; Richter, H.; Smirnov, A.; Günther, B.; Hübers, H.-W.; Il’in, K.; Siegel, M.; Gol’tsman, G.; Drakinskiy, V.; Merkel, H.; Karamarkovic, J.
Title (up) Development of HEB mixers for GREAT and for security screening Type Abstract
Year 2007 Publication Proc. 18th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 18th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 184
Keywords NbN HEB mixers, GREAT
Abstract We report the study on the quasioptical coupling efficiency and the gain bandwidth of NbN hot-electron bolometer mixers developed for the 4.7 THz channel of the German receiver for Astronomy at THz-frequencies (GREAT) and for security screening at subterahertz frequencies. Radiation coupling efficiency and directive properties of integrated lens antennas with log-spiral, log-periodic and double-slot planar feeds coupled to a hot-electron bolometer were experimentally studied at frequencies from 1 THz to 6 THz and compared with simulations based on the method of moments and the physical-optics ray tracing. For all studied antennas the modeled spectral dependence of the coupling efficiency fits to the experimental data obtained with both Fourier transform spectroscopy and noise temperature measurements only if the complex impedance of the bolometer is explicitly taken into account. Our experimental data did not indicate any noticeable contribution of the quantum noise to the system noise temperature. The experimentally observed deviation of the beam pattern from the model prediction increases with frequency and is most likely due to a non- ideality of the presently used lenses. Study of the intermediate frequency mixer gain at local oscillator (LO) frequencies between 2.5 THz and 0.3 THz showed an increase of the gain bandwidth at low LO frequencies that was understood as the contribution of the direct interaction of magnetic vortices with the radiation field. We have found that the non- homogeneous hot-spot model more adequately describes variation of the intermediate frequency bandwidth with the applied local oscillator power than any of uniform mixer models. The state-of-the-day performance of the GREAT 4.7-THz channel and the 0.8-THz security scanner will be presented.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1420
Permanent link to this record
 
 
Author Novotny, Lukas
Title (up) Effective wavelength scaling for optical antennas Type Journal Article
Year 2007 Publication Phys. Rev. Lett. Abbreviated Journal Phys. Rev. Lett.
Volume 98 Issue 26 Pages 266802(1-4)
Keywords optical antennas
Abstract In antenna theory, antenna parameters are directly related to the wavelength λ of incident radiation, but this scaling fails at optical frequencies where metals behave as strongly coupled plasmas. In this Letter we show that antenna designs can be transferred to the optical frequency regime by replacing λ by a linearly scaled effective wavelength λeff=n1+n2λ/λp, with λp being the plasma wavelength and n1, n2 being coefficients that depend on geometry and material properties. It is assumed that the antenna is made of linear segments with radii Râ‰<aa>λ. Optical antennas hold great promise for increasing the efficiency of photovoltaics, light-emitting devices, and optical sensors.
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 749
Permanent link to this record