|   | 
Details
   web
Records
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 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.
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 1414
Permanent link to this record
 

 
Author Ozhegov, R. V.; Okunev, O. V.; Gol’tsman, G. N.; Filippenko, L. V.; Koshelets, V. P.
Title Noise equivalent temperature difference of a superconducting integrated terahertz receiver Type Journal Article
Year 2009 Publication J. Commun. Technol. Electron. Abbreviated Journal J. Commun. Technol. Electron.
Volume 54 Issue 6 Pages 716-720
Keywords SIS mixer SIR NETD, FFO, harmonic mixer
Abstract The dependence of the noise equivalent temperature difference (NETD) of a superconducting integrated receiver (SIR) on the receiver noise temperature and the inputsignal level has been investigated. An unprecedented NETD of 13±2 mK has been measured at a SIR noise temperature of 200 K, intermediate-frequency bandwidth of 4 GHz, and time constant of 1 s. With a decrease in the input signal, an improvement in the NETD is observed. This effect is explained by a reduction in the influence of the instabilities of the receiver power supply and the amplification circuit that occur when the input signal is decreased.
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 Approved no
Call Number Serial 1400
Permanent link to this record
 

 
Author Ozhegov, R. V.; Gorshkov, K. N.; Okunev, O. V.; Gol’tsman, G. N.
Title Superconducting hot-electron bolometer mixer as element of thermal imager matrix Type Journal Article
Year 2010 Publication Tech. Phys. Lett. Abbreviated Journal Tech. Phys. Lett.
Volume 36 Issue 11 Pages 1006-1008
Keywords HEB mixers
Abstract The possibility of using a matrix of sensitive elements on a 12-mm-diameter hyperhemispherical lens in a thermal imager operating in the terahertz range has been studied. Dimensions of a lens region acceptable for arrangement of the matrix, in which the receiver noise temperature varies within 16% of the mean value, are determined to be 3.3% of the lens diameter. Deviations of the main lobe of the directivity pattern are evaluated, which amount to ±1.25° relative to the direction toward the optimum position of a mixer. The fluctuation sensitivity of the receiver measured in experiment is 0.5 K at a frequency of 300 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 1063-7850 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1390
Permanent link to this record
 

 
Author Okunev, O.; Chulkova, G.; Milostnaya, I.; Antipov, A.; Smirnov, K.; Morozov, D.; Korneev, A.; Voronov, B.; Gol’tsman, G.; Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Górska, M.; Pearlman, A.; Cross, A.; Kitaygorsky, J.; Sobolewski, R.
Title Registration of infrared single photons by a two-channel receiver based on fiber-coupled superconducting single-photon detectors Type Conference Article
Year 2008 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 7009 Issue Pages 70090V (1 to 8)
Keywords SSPD, SNSPD, single-photon detectors, superconductors, superconducting nanost
Abstract Single-photon detectors (SPDs) are the foundation of all quantum communications (QC) protocols. Among different classes of SPDs currently studied, NbN superconducting SPDs (SSPDs) are established as the best devices for ultrafast counting of single photons in the infrared (IR) wavelength range. The SSPDs are nanostructured, 100 μm2 in total area, superconducting meanders, patterned by electron lithography in ultra-thin NbN films. Their operation has been explained within a phenomenological hot-electron photoresponse model. We present the design and performance of a novel, two-channel SPD receiver, based on two fiber-coupled NbN SSPDs. The receivers have been developed for fiber-based QC systems, operational at 1.3 μm and 1.55 μm telecommunication wavelengths. They operate in the temperature range from 4.2 K to 2 K, in which the NbN SSPDs exhibit their best performance. The receiver unit has been designed as a cryostat insert, placed inside a standard liquid-heliumstorage dewar. The input of the receiver consists of a pair of single-mode optical fibers, equipped with the standard FC connectors and kept at room temperature. Coupling between the SSPD and the fiber is achieved using a specially designed, precise micromechanical holder that places the fiber directly on top of the SSPD nanostructure. Our receivers achieve the quantum efficiency of up to 7% for near-IR photons, with the coupling efficiency of about 30%. The response time was measured to be < 1.5 ns and it was limited by our read-out electronics. The jitter of fiber-coupled SSPDs is < 35 ps and their dark-count rate is below 1s-1. The presented performance parameters show that our single-photon receivers are fully applicable for quantum correlation-type QC systems, including practical quantum cryptography.
Address
Corporate Author Thesis
Publisher SPIE Place of Publication Editor Sukhoivanov, I.A.; Svich, V.A.; Shmaliy, Y.S.
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 1413
Permanent link to this record
 

 
Author Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Gorska, M.; Rieger, E.; Dorenbos, P.; Zwiller, V.; Milostnaya, I.; Minaeva, O.; Antipov, A.; Okunev, O.; Korneev, A.; Smirnov, K.; Voronov, B.; Kaurova, N.; Gol’tsman, G.N.; Kitaygorsky, J.; Pan, D.; Pearlman, A.; Cross, A.; Komissarov, I.; Sobolewski, R.
Title Fiber-coupled NbN superconducting single-photon detectors for quantum correlation measurements Type Conference Article
Year 2007 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 6583 Issue Pages 65830J (1 to 11)
Keywords NbN SSPD, SNSPD, superconducting single-photon detectors, single-photon detectors, fiber-coupled optical detectors, quantum correlations, superconducting devices
Abstract We have fabricated fiber-coupled superconducting single-photon detectors (SSPDs), designed for quantum-correlationtype experiments. The SSPDs are nanostructured ( 100-nm wide and 4-nm thick) NbN superconducting meandering stripes, operated in the 2 to 4.2 K temperature range, and known for ultrafast and efficient detection of visible to nearinfrared photons with almost negligible dark counts. Our latest devices are pigtailed structures with coupling between the SSPD structure and a single-mode optical fiber achieved using a micromechanical photoresist ring placed directly over the meander. The above arrangement withstands repetitive thermal cycling between liquid helium and room temperature, and we can reach the coupling efficiency of up to  33%. The system quantum efficiency, measured as the ratio of the photons counted by SSPD to the total number of photons coupled into the fiber, in our early devices was found to be around 0.3 % and 1% for 1.55 &mgr;m and 0.9 &mgr;m photon wavelengths, respectively. The photon counting rate exceeded 250 MHz. The receiver with two SSPDs, each individually biased, was placed inside a transport, 60-liter liquid helium Dewar, assuring uninterrupted operation for over 2 months. Since the receiver’s optical and electrical connections are at room temperature, the set-up is suitable for any applications, where single-photon counting capability and fast count rates are desired. In our case, it was implemented for photon correlation experiments. The receiver response time, measured as a second-order photon cross-correlation function, was found to be below 400 ps, with timing jitter of less than 40 ps.
Address
Corporate Author Thesis
Publisher Spie Place of Publication Editor Dusek, M.; Hillery, M.S.; Schleich, W.P.; Prochazka, I.; Migdall, A.L.; Pauchard, A.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Photon Counting Applications, Quantum Optics, and Quantum Cryptography
Notes Approved no
Call Number Serial 1431
Permanent link to this record