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Author Gol’tsman, G. N.; Okunev, O.; Chulkova, G.; Lipatov, A.; Semenov, A.; Smirnov, K.; Voronov, B.; Dzardanov, A.; Williams, C.; Sobolewski, R.
Title Picosecond superconducting single-photon optical detector Type Journal Article
Year 2001 Publication (down) Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 79 Issue 6 Pages 705-707
Keywords NbN SSPD, SNSPD
Abstract We experimentally demonstrate a supercurrent-assisted, hotspot-formation mechanism for ultrafast detection and counting of visible and infrared photons. A photon-induced hotspot leads to a temporary formation of a resistive barrier across the superconducting sensor strip and results in an easily measurable voltage pulse. Subsequent hotspot healing in ∼30 ps time frame, restores the superconductivity (zero-voltage state), and the detector is ready to register another photon. Our device consists of an ultrathin, very narrow NbN strip, maintained at 4.2 K and current-biased close to the critical current. It exhibits an experimentally measured quantum efficiency of ∼20% for 0.81 μm wavelength photons and negligible dark counts.
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Language Summary Language Original Title
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Series Volume Series Issue Edition
ISSN 0003-6951 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1543
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Author Semenov, A. D.; Gousev, Y. P.; Nebosis, R. S.; Renk, K. F.; Yagoubov, P.; Voronov, B. M.; Gol’tsman, G. N.; Syomash, V. D.; Gershenzon, E. M.
Title Heterodyne detection of THz radiation with a superconducting hot‐electron bolometer mixer Type Journal Article
Year 1996 Publication (down) Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 69 Issue 2 Pages 260-262
Keywords NbN HEB mixers
Abstract We report on the use of a superconducting hot‐electron bolometer mixer for heterodyne detection of terahertz radiation. Radiation with a wavelength of 119 μm was coupled to the mixer, a NbN microbridge, by a hybrid quasioptical antenna consisting of an extended hyperhemispherical lens and a planar logarithmic spiral antenna. We found, at an intermediate frequency of 1.5 GHz, a system double side band noise temperature of ≊40 000 K and conversion losses of 25 dB. We also discuss the possibilities of further improvement of the mixer performance.
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Language Summary Language Original Title
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Series Volume Series Issue Edition
ISSN 0003-6951 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1610
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Author Semenov, A. D.; Goghidze, I. G.; Gol’tsman, G. N.; Sergeev, A. V.; Gershenzon, E. M.
Title Evidence for the spectral dependence of nonequilibrium picosecond photoresponse of YBaCuO thin films Type Journal Article
Year 1993 Publication (down) Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 63 Issue 5 Pages 681-683
Keywords YBCO HTS detectors, nonequilibrium
Abstract The transient voltage photoresponse of current biased YBaCuO thin films to 20 ps laser pulses of 0.63 and 1.54 μm wavelengths is measured for temperatures around the superconducting transition region. The fast picosecond decay of the response is followed by a slow nanosecond relaxation which is associated with the bolometric effect. The magnitude of the fast component of the response varies in proportion to the square root of wavelength that plausibly reflects multiplication processes of photoexcited electrons via electron–electron scattering and interaction with high energy phonons.
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Language Summary Language Original Title
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Series Volume Series Issue Edition
ISSN 0003-6951 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1655
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Author Semenov, A. D.; Gol’tsman, G. N.; Gogidze, I. G.; Sergeev, A. V.; Gershenzon, E. M.; Lang, P. T.; Renk, K. F.
Title Subnanosecond photoresponse of a YBaCuO thin film to infrared and visible radiation by quasiparticle induced suppression of superconductivity Type Journal Article
Year 1992 Publication (down) Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 60 Issue 7 Pages 903-905
Keywords YBCO HTS detectors
Abstract We observed subnanosecond photoresponse of a structured superconducting YBa2Cu3O7−δ thin film to infrared and visible radiation. We measured the voltage response of a current biased film (thickness 700 Å) in a resistive state to radiation pulses. From our results we conclude a response time of about 90 ps and a responsivity of about 4×1010 Ω/J. We attribute the response to Cooper pair breaking and suppression of the superconducting energy gap induced by nonequilibrium quasiparticles.
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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 1672
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Author Lang, P. T.; Leipold, I.; Knott, W. J.; Semenov, A. D.; Gol'tsman, G. N.; Renk, K. F.
Title New far-infrared laser lines from CH3Cl and CH3Br optically pumped with a continuously tunable high pressure CO2 laser Type Journal Article
Year 1991 Publication (down) Appl. Phys. B Abbreviated Journal Appl. Phys. B
Volume 53 Issue 4 Pages 207-212
Keywords CO2 IR lasers, applications, CH3Cl, CH3Br
Abstract In this paper we report on the detection of new far-infrared laser lines from CH3Cl and CH3Br optically pumped with a continuously tunable high pressure CO2 laser. We found 80 new lines for CH3Cl and 9 new lines for CH3Br in the frequency region between 16 cm−1 and 41 cm−1, all due to stimulated Raman scattering. For the Raman gain regions bandwidths up to about 700 MHz were found. We also observed high intensity short far-infrared laser pulses of durations in the nanosecond regime.
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Language Summary Language Original Title
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Series Volume Series Issue Edition
ISSN 0721-7269 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1678
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