Kerman AJ, Dauler EA, Keicher WE, Yang JKW, Berggren KK, Gol’tsman G, et al. Kinetic-inductance-limited reset time of superconducting nanowire photon counters. Appl Phys Lett. 2006;88(11):111116 (1 to 3).
Abstract: We investigate the recovery of superconducting NbN-nanowire photon counters after detection of an optical pulse at a wavelength of 1550nm, and present a model that quantitatively accounts for our observations. The reset time is found to be limited by the large kinetic inductance of these nanowires, which forces a tradeoff between counting rate and either detection efficiency or active area. Devices of usable size and high detection efficiency are found to have reset times orders of magnitude longer than their intrinsic photoresponse time.
The authors acknowledge D. Oates and W. Oliver (MIT Lincoln Laboratory), S.W. Nam, A. Miller, and R. Hadfield (NIST) and R. Sobolewski, A. Pearlman, and A. Verevkin (University of Rochester) for helpful discussions and technical assistance. This work made use of MIT’s shared scanning-electron-beam-lithography facility in the Research Laboratory of Electronics. This work is sponsored by the United States Air Force under Air Force Contract No. FA8721-05-C-0002. Opinions, interpretations, recommendations and conclusions are those of the authors and are not necessarily endorsed by the United States Government.
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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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Il'in KS, Verevkin AA, Gol'tsman GN, Sobolewski R. Infrared hot-electron NbN superconducting photodetectors for imaging applications. Supercond Sci Technol. 1999;12(11):755–8.
Abstract: We report an effective quantum efficiency of 340, responsivity >200 A W-1 (>104 V W-1) and response time of 27±5 ps at temperatures close to the superconducting transition for NbN superconducting hot-electron photodetectors (HEPs) in the near-infrared and optical ranges. Our studies were performed on a few nm thick NbN films deposited on sapphire substrates and patterned into µm-size multibridge detector structures, incorporated into a coplanar transmission line. The time-resolved photoresponse was studied by means of subpicosecond electro-optic sampling with 100 fs wide laser pulses. The quantum efficiency and responsivity studies of our photodetectors were conducted using an amplitude-modulated infrared beam, fibre-optically coupled to the device. The observed picosecond response time and the very high efficiency and sensitivity of the NbN HEPs make them an excellent choice for infrared imaging photodetectors and input optical-to-electrical transducers for superconducting digital circuits.
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Pearlman A, Cross A, Slysz W, Zhang J, Verevkin A, Currie M, et al. Gigahertz counting rates of NbN single-photon detectors for quantum communications. IEEE Trans Appl Supercond. 2005;15(2):579–82.
Abstract: We report on the GHz counting rate and jitter of our nanostructured superconducting single-photon detectors (SSPDs). The devices were patterned in 4-nm-thick and about 100-nm-wide NbN meander stripes and covered a 10-/spl mu/m/spl times/10-/spl mu/m area. We were able to count single photons at both the visible and infrared telecommunication wavelengths at rates of over 2 GHz with a timing jitter of below 18 ps. We also present the model for the origin of the SSPD switching dynamics and jitter, based on the time-delay effect in the phase-slip-center formation mechanism during the detector photoresponse process. With further improvements in our readout electronics, we expect that our SSPDs will reach counting rates of up to 10 GHz. An integrated quantum communications receiver based on two fiber-coupled SSPDs and operating at 1550-nm wavelength is also presented.
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Korneev A, Lipatov A, Okunev O, Chulkova G, Smirnov K, Gol’tsman G, et al. GHz counting rate NbN single-photon detector for IR diagnostics of VLSI CMOS circuits. Microelectronic Engineering. 2003;69(2-4):274–8.
Abstract: We present a new, simple to manufacture superconducting single-photon detector operational in the range from ultraviolet to mid-infrared radiation wavelengths. The detector combines GHz counting rate, high quantum efficiency and very low level of dark (false) counts. At 1.3–1.5 μm wavelength range our detector exhibits a quantum efficiency of 5–10%. The detector photoresponse voltage pulse duration was measured to be about 150 ps with jitter of 35 ps and both of them were limited mostly by our measurement equipment. In terms of quantum efficiency, dark counts level, speed of operation the detector surpasses all semiconductor counterparts and was successfully applied for CMOS integrated circuits diagnostics.
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