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Gol’tsman GN, Gershenzon EM. High speed hot-electron superconducting bolometer. In: Birch JR, Parker TJ, editors. Proc. SPIE. Vol 2104. SPIE; 1993. p. 181–2.
Abstract: Physical limitation of response time of a superconducting bolometer as well as the nature of non-equilibrium detection of radiation have been investigated for Al, Nb and NbN thin films in spectral range from submillimeter to near-infraredwavelengths [1,2]. In the case of ideal heat removal from the film with the f_‘. 100A thickness the detection mechanism is an electron heating effect that is not selective to radiation wavelength in a very broad range. The response time ofan electron heating bolometer is determined by an electron-phonon interaction time. This time is of about 10 ns, 0.5 ns and 20 ps for Al, Nb, and NbN correspondingly near the critical temperature of the superconducting film. Thesensitive area of the bolometer consists of a number of narrow strips (with awidth of 1µm) connected in parallel to contact pads; these pads together witha sapphire substrate and a ground plate represent the microstrip transmissionline with an impedance of 50 Q.
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Zhang J, Verevkin A, Slysz W, Chulkova G, Korneev A, Lipatov A, et al. Time-resolved characterization of NbN superconducting single-photon optical detectors. In: Armitage JC, editor. Proc. SPIE. Vol 10313. SPIE; 2017. 103130F (1 to 3).
Abstract: NbN superconducting single-photon detectors (SSPDs) are very promising devices for their picosecond response time, high intrinsic quantum efficiency, and high signal-to-noise ratio within the radiation wavelength from ultraviolet to near infrared (0.4 gm to 3 gm) [1-3]. The single photon counting property of NbN SSPDs have been investigated thoroughly and a model of hotspot formation has been introduced to explain the physics of the photon- counting mechanism [4-6]. At high incident flux density (many-photon pulses), there are, of course, a large number of hotspots simultaneously formed in the superconducting stripe. If these hotspots overlap with each other across the width w of the stripe, a resistive barrier is formed instantly and a voltage signal can be generated. We assume here that the stripe thickness d is less than the electron diffusion length, so the hotspot region can be considered uniform. On the other hand, when the photon flux is so low that on average only one hotspot is formed across w at a given time, the formation of the resistive barrier will be realized only when the supercurrent at sidewalks surpasses the critical current (jr) of the superconducting stripe [1]. In the latter situation, the formation of the resistive barrier is associated with the phase-slip center (PSC) development. The effect of PSCs on the suppression of superconductivity in nanowires has been discussed very recently [8, 9] and is the subject of great interest.
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Manova NN, Simonov NO, Korneeva YP, Korneev AA. Developing of NbN films for superconducting microstrip single-photon detector. In: J. Phys.: Conf. Ser. Vol 1695.; 2020. 012116 (1 to 5).
Abstract: We optimized NbN films on a Si substrate with a buffer SiO2 layer to produce superconducting microstrip single-photon detectors with saturated dependence of quantum efficiency (QE) versus normalized bias current. We varied thickness of films and observed the maximum QE saturation for device based on the thinner film with the lowest ratio RS300/RS20.
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Polyakova MI, Korneev AA, Semenov AV. Comparison single- and double- spot detection efficiencies of SSPD based to MoSi and NbN films. In: J. Phys.: Conf. Ser. Vol 1695.; 2020. 012146 (1 to 3).
Abstract: In this work, we present results of quantum detector tomography of superconducting single photon detector (SSPD) based on MoSi film, and compare them with previously reported data on NbN. We find that for both materials hot spot interaction length coincides with the strip width, and the dependence of single and double-spot detection efficiencies on bias current are compatible with sufficiently large hot-spot size, approaching the strip width.
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Antipov AV, Seleznev VA, Vakhtomin YB, Morozov PV, Vasilev DD, Malevannaya EI, et al. Investigation of WSi and NbN superconducting single-photon detectors in mid-IR range. In: IOP Conf. Ser.: Mater. Sci. Eng. Vol 781.; 2020. 012011 (1 to 5).
Abstract: Spectral characteristics of WSi and NbN superconducting single-photon detectors with different surface resistance and width of nanowire strips have been investigated in the wavelength range of 1.3-2.5 μm. WSi structures with narrower strips demonstrated better performance for detection of single photons in longer wavelength range. The difference in normalized photon count rate for such structures reaches one order of magnitude higher in comparison with structures based on NbN thin films at 2.5 μm.
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Kuznetsov KA, Kornienko VV, Vakhtomin YB, Pentin IV, Smirnov KV, Kitaeva GK. Generation and detection of optical-terahertz biphotons via spontaneous parametric downconversion. In: Proc. ICLO.; 2018. 303.
Abstract: We study spontaneous parametric downconversion (SPDC) in the strongly non-degenerate regime when the idler wave hits the terahertz range. By using the hot-electron bolometer, for the first time the SPDC-generated idler-wave photons were directly detected in the terahertz frequency range. Spectrum of corresponding signal photons was measured using standard technique by the CCD camera. Possible applications of correlated optical-terahertz biphotons are discussed.
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Schroeder E, Mauskopf P, Pilyavsky G, Sinclair A, Smith N, Bryan S, et al. On the measurement of intensity correlations from laboratory and astronomical sources with SPADs and SNSPDs. In: Malbet F, Creech-Eakman MJ, Tuthill PG, editors. Proc. SPIE. Vol 9907. SPIE; 2016. 99070P (1 to 13).
Abstract: We describe the performance of detector modules containing silicon single photon avalanche photodiodes (SPADs) and superconducting nanowire single photon detectors (SNSPDs) to be used for intensity interferometry. The SPADs are mounted in fiber-coupled and free-space coupled packages. The SNSPDs are mounted in a small liquid helium cryostat coupled to single mode fiber optic cables which pass through a hermetic feed-through. The detectors are read out with microwave amplifiers and FPGA-based coincidence electronics. We present progress on measurements of intensity correlations from incoherent sources including gas-discharge lamps and stars with these detectors. From the measured laboratory performance of the correlation system, we estimate the sensitivity to intensity correlations from stars using commercial telescopes and larger existing research telescopes.
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Hübers H-W, Semenov A, Richter H, Birk M, Krocka M, Mair U, et al. Terahertz heterodyne receiver with a hot-electron bolometer mixer. In: Wold J, Davidson J, editors. Proc. Far-IR, Sub-mm, and mm Detector Technology Workshop.; 2002.
Abstract: During the past decade major advances have been made regarding low noise mixers for terahertz (THz) heterodyne receivers. State of the art hot-electron-bolometer (HEB) mixers have noise temperatures close to the quantum limit and require less than a µW power from the local oscillator (LO). The technology is now at a point where the performance of a practical receiver employing such mixer, rather than the figures of merit of the mixer itself, are of major concern. We have incorporated a phonon-cooled NbN HEB mixer in a 2.5 THz heterodyne receiver and investigated the performance of the receiver. This yields important information for the development of heterodyne receivers such as GREAT (German receiver for astronomy at THz frequencies aboard SOFIA)[1] and TELIS (Terahertz limb sounder), a balloon borne heterodyne receiver for atmospheric research [2]. Both are currently under development at DLR.
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Селиверстов СВ, Финкель МИ, Рябчун СА, Воронов БМ, Каурова НС, Селезнев ВА, et al. Терагерцевый сверхпроводниковый детектор с аттоджоулевым энергетическим разрешением и постоянной времени 25 пс. In: Труды XVIII международного симпозиума «Нанофизика и наноэлектроника». Vol 1.; 2014. p. 91–2.
Abstract: Представлены результаты измерения энергетического разрешения терагерцевого сверхпроводникового NbN-детектора на эффектеэлектронного разогрева, работающего при температуре около 10 К. Использование инновационной in situ технологии производства привело к существенному улучшению чувствительности детектора. Увеличение быстродействия детектора было достигнуто за счет реализации дополнительного диффузионного канала охла-ждения электронной подсистемы. Измеренное значение эквивалентной мощности шума на частоте 2.5 ТГц составило 2.0×10-13Вт•Гц-0.5, постоянной времени 25 пс. Соответствующее расчетное значение энергетического разрешения составило 2.5 аДж.
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Hajenius M, Baselmans JJA, Gao JR, Klapwijk TM, de Korte PAJ, Voronov B, et al. Low noise NbN superconducting hot electron bolometer mixers at 1.9 and 2.5 THz. Supercond Sci Technol. 2004;17(5):S224–S228.
Abstract: NbN phonon-cooled hot electron bolometer mixers (HEBs) have been realized with negligible contact resistance between the bolometer itself and the contact structure. Using a combination of in situ cleaning of the NbN film and the use of an additional superconducting interlayer of a 10 nm NbTiN layer between the Au of the contact structure and the NbN film superior noise temperatures have been obtained as low as 950 K at 2.5 THz and 750 K at 1.9 THz. Here we address in detail the DC characterization of these devices, the interface transparencies between the bolometers and the contacts and the consequences of these factors on the mixer performance.
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