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Author Słysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Górska, M.; Zwiller, V.; Latta, C.; Böhi, P.; Pearlman, A.J.; Cross, A.S.; Pan, D.; Kitaygorsky, J.; Komissarov, I.; Verevkin, A.; Milostnaya, I.; Korneev, A.; Minayeva, O.; Chulkova, G.; Smirnov, K.; Voronov, B.; Gol’tsman, G.N.; Sobolewski, R.
Title Fibre-coupled, single photon detector based on NbN superconducting nanostructures for quantum communications Type Journal Article
Year 2007 Publication J. Modern Opt. Abbreviated Journal J. Modern Opt.
Volume (down) 54 Issue 2-3 Pages 315-326
Keywords NbN SSPD, SNSPD
Abstract We present a novel, two-channel, single photon receiver based on two fibre-coupled, NbN, superconducting, single photon detectors (SSPDs). The SSPDs are nanostructured superconducting meanders and are known for ultrafast and efficient detection of visible-to-infrared photons. Coupling between the NbN detector and optical fibre was achieved using a micromechanical photoresist ring placed directly over the SSPD, holding the fibre in place. With this arrangement, we obtained coupling efficiencies up to ∼30%. Our experimental results showed that the best receiver had a near-infrared system quantum efficiency of 0.33% at 4.2 K. The quantum efficiency increased exponentially with the photon energy increase, reaching a few percent level for visible-light photons. The photoresponse pulses of our devices were limited by the meander high kinetic inductance and had the rise and fall times of approximately 250 ps and 5 ns, respectively. The receiver's timing jitter was in the 37 to 58 ps range, approximately 2 to 3 times larger than in our older free-space-coupled SSPDs. We stipulate that this timing jitter is in part due to optical fibre properties. Besides quantum communications, the two-detector arrangement should also find applications in quantum correlation experiments.
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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 0950-0340 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1434
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Author Verevkin, A.; Pearlman, A.; Slysz, W.; Zhang, J.; Currie, M.; Korneev, A.; Chulkova, G.; Okunev, O.; Kouminov, P.; Smirnov, K.; Voronov, B.; Gol'tsman, G. N.; Sobolewski, R.
Title Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications Type Journal Article
Year 2004 Publication J. Modern Opt. Abbreviated Journal J. Modern Opt.
Volume (down) 51 Issue 9-10 Pages 1447-1458
Keywords NbN SSPD, SNSPD
Abstract The paper reports progress on the design and development of niobium-nitride, superconducting single-photon detectors (SSPDs) for ultrafast counting of near-infrared photons for secure quantum communications. The SSPDs operate in the quantum detection mode, based on photon-induced hotspot formation and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-width superconducting stripe. The devices are fabricated from 3.5 nm thick NbN films and kept at cryogenic (liquid helium) temperatures inside a cryostat. The detector experimental quantum efficiency in the photon-counting mode reaches above 20% in the visible radiation range and up to 10% at the 1.3–1.55 μn infrared range. The dark counts are below 0.01 per second. The measured real-time counting rate is above 2 GHz and is limited by readout electronics (the intrinsic response time is below 30 ps). The SSPD jitter is below 18 ps, and the best-measured value of the noise-equivalent power (NEP) is 2 × 10−18 W/Hz1/2. at 1.3 μm. In terms of photon-counting efficiency and speed, these NbN SSPDs significantly outperform semiconductor avalanche photodiodes and photomultipliers.
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 0950-0340 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1488
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Author Lusche, Robert; Semenov, Alexey; Huebers, Heinz-Willhelm; Ilin, Konstantin; Siegel, Michael; Korneeva, Yuliya; Trifonov, Andrey; Korneev, Alexander; Goltsman, Gregory
Title Effect of the wire geometry and an externally applied magnetic field on the detection efficiency of superconducting nanowire single-photon detectors Type Abstract
Year 2013 Publication INIS Abbreviated Journal INIS
Volume (down) 46 Issue 8 Pages 1-3
Keywords TaN, NbN SSPD, SNSPD
Abstract The interest in single-photon detectors in the near-infrared wavelength regime for applications, e.g. in quantum cryptography has immensely increased in the last years. Superconducting nanowire single-photon detectors (SNSPD) already show quite reasonable detection efficiencies in the NIR which can even be further improved. Novel theoretical approaches including vortex-assisted photon counting state that the detection efficiency in the long wavelength region can be enhanced by the detector geometry and an applied magnetic field. We present spectral measurements in the wavelength range from 350-2500 nm of the detection efficiency of meander-type TaN and NbN SNSPD with varying nanowire line width from 80 to 250 nm. Due to the used experimental setup we can accurately normalize the measured spectra and are able to extract the intrinsic detection efficiency (IDE) of our detectors. The results clearly indicate an improvement of the IDE depending on the wire width according to the theoretic models. Furthermore we experimentally found that the smallest detectable photon-flux can be increased by applying a small magnetic field to the detectors.
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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 1374
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Author Słysz, W.; Węgrzecki, M.; Bar, J.; Grabiec, P.; Gol'tsman, G. N.; Verevkin, A.; Sobolewski, R.
Title NbN superconducting single-photon detector coupled with a communication fiber Type Journal Article
Year 2005 Publication Elektronika : konstrukcje, technologie, zastosowania Abbreviated Journal
Volume (down) 46 Issue 6 Pages 51-52
Keywords NbN SSPD, SNSPD
Abstract We present novel superconducting single-photon detectors (SSPDs), ba­sed on ultrathin NbN films, designed for fiber-based quantum communica­tions (lambda = 1.3 žm and 1.55 žm). For fiber-based operation, our SSPDs contain a special micromechanical construction integrated with the NbN structure, which enables efficient and mechanically very stabile fiber coupling. The detectors combine GHz counting rate, high quantum efficiency and very low level of dark counts. At 1.3 – 1.55 žm wavelength range our detector exhibits a quantum efficiency up to 10%.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Polish 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 1481
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Author Milostnaya, I.; Korneev, A.; Rubtsova, I.; Seleznev, V.; Minaeva, O.; Chulkova, G.; Okunev, O.; Voronov, B.; Smirnov, K.; Gol'tsman, G.; Slysz, W.; Wegrzecki, M.; Guziewicz, M.; Bar, J.; Gorska, M.; Pearlman, A.; Kitaygorsky, J.; Cross, A.; Sobolewski, R.
Title Superconducting single-photon detectors designed for operation at 1.55-µm telecommunication wavelength Type Conference Article
Year 2006 Publication J. Phys.: Conf. Ser. Abbreviated Journal J. Phys.: Conf. Ser.
Volume (down) 43 Issue Pages 1334-1337
Keywords NbN SSPD, SNSPD
Abstract We report on our progress in development of superconducting single-photon detectors (SSPDs), specifically designed for secure high-speed quantum communications. The SSPDs consist of NbN-based meander nanostructures and operate at liquid helium temperatures. In general, our devices are capable of GHz-rate photon counting in a spectral range from visible light to mid-infrared. The device jitter is 18 ps and dark counts can reach negligibly small levels. The quantum efficiency (QE) of our best SSPDs for visible-light photons approaches a saturation level of ~30-40%, which is limited by the NbN film absorption. For the infrared range (1.55µm), QE is ~6% at 4.2 K, but it can be significantly improved by reduction of the operation temperature to the 2-K level, when QE reaches ~20% for 1.55-µm photons. In order to further enhance the SSPD efficiency at the wavelength of 1.55 µm, we have integrated our detectors with optical cavities, aiming to increase the effective interaction of the photon with the superconducting meander and, therefore, increase the QE. A successful effort was made to fabricate an advanced SSPD structure with an optical microcavity optimized for absorption of 1.55 µm photons. The design consisted of a quarter-wave dielectric layer, combined with a metallic mirror. Early tests performed on relatively low-QE devices integrated with microcavities, showed that the QE value at the resonator maximum (1.55-µm wavelength) was of the factor 3-to-4 higher than that for a nonresonant SSPD. Independently, we have successfully coupled our SSPDs to single-mode optical fibers. The completed receivers, inserted into a liquid-helium transport dewar, reached ~1% system QE for 1.55 µm photons. The SSPD receivers that are fiber-coupled and, simultaneously, integrated with resonators are expected to be the ultimate photon counters for optical quantum communications.
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 1742-6588 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1450
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