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Author Gol’tsman, G. N.; Kouminov, P. B.; Goghidze, I. G.; Karasik, B. S.; Gershenzon, E. M. url  doi
openurl 
  Title Nonbolometric and fast bolometric responses of YBaCuO thin films in superconducting, resistive, and normal states Type Conference Article
  Year 1994 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 2159 Issue Pages 81-86  
  Keywords YBCO HTS HEB, nonbolornetric  
  Abstract The transient voltage response in both epitaxial and granular YBaCuO thin films to 20 ps pulses of YAG:Nd laser radiation with 0.63 micrometers and 1.54 micrometers was studied. In normal and resistive states both types of films demonstrate two components: nonequilibrium picosecond component and following bolometric nanosecond. The normalized amplitudes are almost the same for all films. In superconducting state we observed a kinetic inductive response and two-component shape after integration. The normalized amplitude of the response in granular films is up to several orders of magnitude larger than in epitaxial films. We interpret the nonequilibrium response in terms of a suppression of order parameter by the excess of quasiparticles followed by the change of resistance in normal and resistive states or kinetic inductance in superconducting state. The sharp rise of inductive response in granular films is explained both by a diminishing of the crossection for current percolation through the disordered network os Josephson weak links and by a decrease of condensate density in neighboring regions.  
  Address  
  Corporate Author Thesis  
  Publisher SPIE Place of Publication Editor Nahum, M.; Villegier, J.-C.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference (up) High-Temperature Superconducting Detectors: Bolometric and Nonbolometric  
  Notes Approved no  
  Call Number Serial 1641  
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Author Blundell, R.; Kawamura, J. H.; Tong, C. E.; Papa, D. C.; Hunter, T. R.; Gol’tsman, G. N.; Cherednichenko, S. I.; Voronov, B. M.; Gershenzon, E. M. url  doi
isbn  openurl
  Title A hot-electron bolometer mixer receiver for the 680-830 GHz frequency range Type Conference Article
  Year 1998 Publication Proc. 6-th Int. Conf. Terahertz Electron. Abbreviated Journal Proc. 6-th Int. Conf. Terahertz Electron.  
  Volume Issue Pages 18-20  
  Keywords NbN HEB mixers  
  Abstract We describe a heterodyne receiver designed to operate in the partially transparent atmospheric windows centered on 680 and 830 GHz. The receiver incorporates a niobium nitride thin film, cooled to 4.2 K, as the phonon-cooled hot-electron mixer element. The double sideband receiver noise, measured over the frequency range 680-830 GHz, is typically 700-1300 K. The instantaneous output bandwidth of the receiver is 600 MHz. This receiver has recently been used at the SubMillimeter Telescope, jointly operated by the Steward Observatory and the Max Planck Institute for Radioastronomy, for observations of the neutral carbon and CO spectral lines at 810 GHz and at 806 and 691 GHz respectively. Laboratory measurements on a second mixer in the same test receiver have yielded extended high frequency performance to 1 THz.  
  Address Leeds, UK  
  Corporate Author Thesis  
  Publisher IEEE Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN 0-7803-4903-2 Medium  
  Area Expedition Conference (up) IEEE Sixth International Conference on Terahertz Electronics Proceedings. THZ 98. (Cat. No.98EX171)  
  Notes Approved no  
  Call Number Serial 1581  
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Author Yagoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Schubert, J.; Hubers, H.-W.; Schwaab, G.; Gol’tsman, G.; Gershenzon, E. url  doi
openurl 
  Title Performance of NbN phonon-cooled hot-electron bolometric mixer at Terahertz frequencies Type Conference Article
  Year 1998 Publication Proc. 6-th Int. Conf. Terahertz Electron. Abbreviated Journal Proc. 6-th Int. Conf. Terahertz Electron.  
  Volume Issue Pages 149-152  
  Keywords NbN HEB mixers  
  Abstract The performance of a NbN based phonon-cooled Hot Electron Bolometric (HEB) quasioptical mixer is investigated in the 0.65-3.12 THz frequency range. The device is made from a 3 nm thick NbN film on high resistivity Si and integrated with a planar spiral antenna on the same substrate. The in-plane dimensions of the bolometer strip are 0.2/spl times/2 /spl mu/m. The results of the DSB noire temperature are: 1300 K at 650 GHz, 4700 K at 2.5 TBz and 10000 K at 3.12 THz. The RF bandwidth of the receiver is at least 2.5 THz. The amount of LO power absorbed in the bolometer is about 100 nW. The mixer is linear to within 1 dB compression up to the signal level 10 dB below that of the LO. The intrinsic single sideband conversion gain is measured to be -9 dB, the total conversion gain -14 dB.  
  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 (up) IEEE Sixth International Conference on Terahertz Electronics Proceedings. THZ 98. (Cat. No.98EX171)  
  Notes Approved no  
  Call Number Serial 1582  
Permanent link to this record
 

 
Author Milostnaya, I.; Korneev, A.; Minaeva, O.; Rubtsova, I.; Slepneva, S.; Seleznev, V.; Chulkova, G.; Okunev, O.; Smirnov, K.; Voronov, B.; Gol’tsman, G.; Slysz, W.; Kitaygorsky, J.; Cross, A.; Pearlman, A.; Sobolewski, R. url  doi
openurl 
  Title Superconducting nanostructured detectors capable of single photon counting of mid-infrared optical radiation Type Conference Article
  Year 2005 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 5957 Issue Pages 59570A (1 to 9)  
  Keywords SSPD, SNSPD, single-photon detectors, superconductors, superconducting  
  Abstract We report on our progress in research and development of ultrafast superconducting single-photon detectors (SSPDs) based on ultrathin NbN nanostructures. Our SSPDs were made of the 4-nm-thick NbN films with Tc 11 K, patterned as meander-shaped, 100-nm-wide strips, and covering an area of 10×10 μm2. The detectors exploit a combined detection mechanism, where upon a single-photon absorption, a hotspot of excited electrons and redistribution of the biasing supercurrent, jointly produce a picosecond voltage transient signal across the superconducting nanostripe. The SSPDs are typically operated at 4.2 K, but their sensitivity in the infrared radiation range can be significantly improved by lowering the operating temperature from 4.2 K to 2 K. When operated at 2 K, the SSPD quantum efficiency (QE) for visible light photons reaches 30-40%, which is the saturation value limited by the optical absorption of our 4-nm-thick NbN film. With the wavelength increase of the incident photons,the QE of SSPDs decreases significantly, but even at the wavelength of 6 μm, the detector is able to count single photons and exhibits QE of about 10-2 %. The dark (false) count rate at 2 K is as low as 2x10-4 s,-1 which makes our detector essentially a background-limited sensor. The very low dark-count rate results in a noise equivalent power (NEP) below 10-18 WHz-1/2 for the mid-infrared range (6 μm). Further improvement of the SSPD performance in the mid-infrared range can be obtained by substituting NbN for another, lower-Tc materials with a narrow superconducting gap and low quasiparticles diffusivity. The use of such superconductors should shift the cutoff wavelength below 10 μm.  
  Address  
  Corporate Author Thesis  
  Publisher SPIE Place of Publication Editor Rogalski, A.; Dereniak, E.L.; Sizov, F.F.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference (up) Infrared Photoelectronics  
  Notes Approved no  
  Call Number Serial 1458  
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Author Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Górska, M.; Latta, C.; Zwiller, V.; Pearlman, A.; Cross, A.; Korneev, A.; Kouminov, P.; Smirnov, K.; Voronov, B.; Gol’tsman, G.; Verevkin, A.; Currie, M.; Sobolewski, R. url  doi
openurl 
  Title Fiber-coupled quantum-communications receiver based on two NbN superconducting single-photon detectors Type Conference Article
  Year 2005 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 5957 Issue Pages 59571K (1 to 10)  
  Keywords SSPD, SNSPD, single-photon detectors, quantum communication, quantum cryptography, superconductors, infrared optical detectors  
  Abstract We present the design and performance of a novel, two-channel single-photon receiver, based on two fiber-coupled NbN superconducting single-photon detectors (SSPDs). The SSPDs are nanostructured superconducting meanders covering an area of 100 μm2 and are known for ultrafast and efficient counting of single, visible-to-infrared photons. Their operation has been explained within a phenomenological hot-electron photoresponse model. Our receiver is intended for fiber-based quantum cryptography and communication systems, operational at near-infrared (NIR) telecommunication wavelengths, λ = 1.3 μm and λ = 1.55 μm. Coupling between the NbN detector and a single-mode optical fiber was achieved using a specially designed, micromechanical photoresist ring, positioned directly over the SSPD active area. The positioning accuracy of the ring was below 1 μm. The receiver with SSPDs was placed (immersed) in a standard liquid-helium transport Dewar and kept without interruption for over two months at 4.2 K. At the same time, the optical fiber inputs and electrical outputs were kept at room temperature. Our best system reached a system quantum efficiency of up to 0.3 % in the NIR radiation range, with the detector coupling efficiency of about 30 %. The response time was measured to be about 250 ps and was limited by our read-out electronics. The measured jitter was close to 35 ps. The presented performance parameters show that our NIR single photon detectors are suitable for practical quantum cryptography and for applications in quantum-correlation experiments.  
  Address  
  Corporate Author Thesis  
  Publisher SPIE Place of Publication Editor Rogalski, A.; Dereniak, E.L.; Sizov, F.F.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference (up) Infrared Photoelectronics  
  Notes Approved no  
  Call Number Serial 1459  
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