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Author Smirnov, K. V.; Vachtomin, Y. B.; Ozhegov, R. V.; Pentin, I. V.; Slivinskaya, E. V.; Korneev, A. A.; Goltsman, G. N.
Title Fiber coupled single photon receivers based on superconducting detectors for quantum communications and quantum cryptography Type Conference Article
Year 2008 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 7138 Issue Pages 713827 (1 to 6)
Keywords SSPD, SNSPD, superconducting single photon detector, ultra-thin superconducting films, optical fiber coupling, ready to use receiver
Abstract (up) At present superconducting detectors become increasingly attractive for various practical applications. In this paper we present results on the depelopment of fiber coupled receiver systems for the registration of IR single photons, optimized for telecommunication and quantum-cryptography. These receiver systems were developed on the basis of superconducting single photon detectors (SSPD) of VIS and IR wavelength ranges. The core of the SSPD is a narrow ( 100 nm) and long ( 0,5 mm) strip in the form of a meander which is patterned from a 4-nm-thick NbN film (TC=10-11 K, jC= 5-7•106 A/cm2); the sensitive area dimensions are 10×10 μm2. The main problem to be solved while the receiver system development was optical coupling of a single-mode fiber (9 microns in diameter) with the SSPD sensitive area. Characteristics of the developed system at the optical input are as follows: quantum efficiency >10 % (at 1.3 μm), >4 % (at 1.55 μm); dark counts rate ≤1 s-1; duration of voltage pulse ≤5 ns; jitter ≤40 ps. The receiver systems have either one or two identical channels (for the case of carrying out correlation measurements) and are made as an insert in a helium storage Dewar.
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Publisher Spie Place of Publication Editor Tománek, P.; Senderáková, D.; Hrabovský, M.
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Area Expedition Conference
Notes Approved no
Call Number Serial 1405
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Author Jukna, A.; Kitaygorsky, J.; Pan, D.; Cross, A.; Perlman, A.; Komissarov, I.; Sobolewski, R.; Okunev, O.; Smirnov, K.; Korneev, A.; Chulkova, G.; Milostnaya, I.; Voronov, B.; Gol'tsman, G.
Title Dynamics of hotspot formation in nanostructured superconducting stripes excited with single photons Type Journal Article
Year 2008 Publication Acta Physica Polonica A Abbreviated Journal Acta Physica Polonica A
Volume 113 Issue 3 Pages 955-958
Keywords SSPD, SNSPD
Abstract (up) Dynamics of a resistive hotspot formation by near-infrared-wavelength single photons in nanowire-type superconducting NbN stripes was investigated. Numerical simulations of ultrafast thermalization of photon-excited nonequilibrium quasiparticles, their multiplication and out-diffusion from a site of the photon absorption demonstrate that 1.55 μm wavelength photons create in an ultrathin, two-dimensional superconducting film a resistive hotspot with the diameter which depends on the photon energy, and the nanowire temperature and biasing conditions. Our hotspot model indicates that under the subcritical current bias of the 2D stripe, the electric field penetrates the superconductor at the hotspot boundary, leading to suppression of the stripe superconducting properties and accelerated development of a voltage transient across the stripe.
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Notes Approved no
Call Number Serial 1414
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Author Jiang, Leaf A.; Luu, Jane X.
Title Heterodyne detection with a weak local oscillator Type Journal Article
Year 2008 Publication Appl. Opt. Abbreviated Journal Appl. Opt.
Volume 47 Issue 10 Pages 1486-1503
Keywords weak local oscillator, weak LO, photon-counting detector, photon-counting mixer, counter detector, counter mixer, PD mixer, PCD mixer
Abstract (up) eterodyne detection in the limit of weak (a few photons) local oscillator and signal power levels has been largely neglected in the past, as authors almost always assumed that the noise was dominated by the shot noise from a strong local oscillator. We present the theory for heterodyne detection of diffuse and specular targets at arbitrary power levels, including the case where the local oscillator power is only a few photons per coherent integration period. The theory was tested with experimental results, and was found to show good agreement. We show how to interpret the power spectral density of the heterodyne signal and how to determine the optimal number of signal and local oscillator photons per coherent integration.
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Notes Approved no
Call Number Serial 979
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Author Cherednichenko, S.; Drakinskiy, V.
Title Low noise hot-electron bolometer mixers for terahertz frequencies Type Journal Article
Year 2008 Publication J. Low Temp. Phys. Abbreviated Journal J. Low Temp. Phys.
Volume 151 Issue 1-2 Pages 575-579
Keywords HEB, mixer, gain bandwidth, MgB2
Abstract (up) Hot-electron bolometer (HEB) mixers are used in many low noise heterodyne radio astronomical receivers. Their noise temperature is at the level of 10–15 times the quantum limit. However, their gain bandwidth is a serious limiting factor. Here we review the state of the art of the HEB mixers gain bandwidth for different materials and substrates. We compare the gain bandwidth of HEB mixers made on bulk substrates and thin membranes. Finally, results for MgB2 thin films for broadband HEB mixers are discussed.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2291 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ lobanovyury @ Serial 553
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Author Zhang, W.; Li, N.; Jiang, L.; Ren, Y.; Yao, Q.-J.; Lin, Z.-H.; Shi, S.-C.; Voronov, B. M.; Gol’tsman, G. N.
Title Dependence of noise temperature of quasi-optical superconducting hot-electron bolometer mixers on bath temperature and optical-axis displacement Type Conference Article
Year 2008 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 6840 Issue Pages 684007 (1 to 8)
Keywords NbN HEB mixers, noise temperature, LO power
Abstract (up) It is known that the increase of bath temperature results in the decrease of critical current of superconducting hot-electron bolometer (HEB) mixers owing to the depression of superconductivity, thus leading to the degradation of the mixer’s sensitivity. Here we report our study on the effect of bath temperature on the heterodyne mixing performance of quasi-optical superconducting NbN HEB mixers incorporated with a two-arm log-spiral antenna. The correlation between the bath temperature, critical current, LO power requirement and noise temperature is investigated at 0.5 THz. Furthermore, the heterodyne mixing performance of quasi-optical superconducting NbN HEB mixers is examined while there is an optical-axis displacement between the center of the extended hemispherical silicon lens and the superconducting NbN HEB device, which is placed on the back of the lens. Detailed experimental results and analysis are presented.
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Publisher Spie Place of Publication Editor Zhang, C.; Zhang, X.-C.
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ISSN ISBN Medium
Area Expedition Conference Terahertz Photonics
Notes Approved no
Call Number Serial 1415
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