|
|
Korneeva, Y. P., Vodolazov, D. Y., Semenov, A. V., Florya, I. N., Simonov, N., Baeva, E., et al. (2018). Optical single photon detection in micron-scaled NbN bridges. arXiv:1802.02881v1 [cond-mat.supr-con]. Retrieved June 29, 2024, from https://arxiv.org/abs/1802.02881v1
Abstract: We demonstrate experimentally that single photon detection can be achieved in micron-wide NbN bridges, with widths ranging from 0.53 μm to 5.15 μm and for photon-wavelengths from 408 nm to 1550 nm. The microbridges are biased with a dc current close to the experimental critical current, which is estimated to be about 50 % of the theoretically expected depairing current. These results offer an alternative to the standard superconducting single-photon detectors (SSPDs), based on nanometer scale nanowires implemented in a long meandering structure. The results are consistent with improved theoretical modelling based on the theory of non-equilibrium superconductivity including the vortex-assisted mechanism of initial dissipation.
|
|
|
|
Korneeva, Y. P., Manova, N. N., Dryazgov, M. A., Simonov, N. O., Zolotov, P. I., & Korneev, A. A. (2021). Influence of sheet resistance and strip width on the detection efficiency saturation in micron-wide superconducting strips and large-area meanders. Supercond. Sci. Technol., 34(8), 084001.
Abstract: We report our study of detection efficiency (DE) saturation in wavelength range 400 – 1550 nm for the NbN Superconducting Microstrip Single-Photon Detectors (SMSPD) featuring the strip width up to 3 μm. We observe an expected decrease of the $DE$ saturation plateau with the increase of photon wavelength and decrease of film sheet resistance. At 1.7 K temperature DE saturation can be clearly observed at 1550 nm wavelength in strip with the width up to 2 μm when sheet resistance of the film is above 630Ω/sq. In such strips the length of the saturation plateau almost does not depend on the strip width. We used these films to make meander-shaped detectors with the light sensitive area from 20×20μm2 to a circle 50 μm in diameter. In the latter case, the detector with the strip width of 0.49 μm demonstrates saturation of DE up to 1064 nm wavelength. Although DE at 1310 and 1550 nm is not saturated, it is as high as 60%. The response time is limited by the kinetic inductance and equals to 20 ns(by 1/e decay), timing jitter is 44 ps. When coupled to multi-mode fibre large-area meanders demonstrate significantly higher dark count rate which we attribute to thermal background photons, thus advanced filtering technique would be required for practical applications.
|
|
|
|
Korneeva, Y., Florya, I., Semenov, A., Korneev, A., & Goltsman, G. (2011). New generation of nanowire NbN superconducting single-photon detector for mid-infrared. IEEE Trans. Appl. Supercond., 21(3), 323–326.
Abstract: We present a break-through approach to mid-infrared single-photon detection based on nanowire NbN superconducting single-photon detectors (SSPD). Although SSPD became a mature technology for telecom wavelengths (1.3-1.55 μm) its further expansion to mid-infrared wavelength was hampered by low sensitivity above 2 μm. We managed to overcome this limit by reducing the nanowire width to 50 nm, while retaining high superconducting properties and connecting the wires in parallel to produce a voltage response of sufficient magnitude. The new device exhibits 10 times better quantum efficiency at 3.5 μm wavelength than the “standard” SSPD.
|
|
|
|
Korneev, A. A., Korneeva, Y. P., Mikhailov, M. Y., Pershin, Y. P., Semenov, A. V., Vodolazov, D. Y., et al. (2015). Characterization of MoSi superconducting single-photon detectors in the magnetic field. IEEE Trans. Appl. Supercond., 25(3), 2200504 (1 to 4).
Abstract: We investigate the response mechanism of nanowire superconducting single-photon detectors (SSPDs) made of amorphous MoxSi1-x. We study the dependence of photon count and dark count rates on bias current in magnetic fields up to 113 mT at 1.7 K temperature. The observed behavior of photon counts is similar to the one recently observed in NbN SSPDs. Our results show that the detecting mechanism of relatively high-energy photons does not involve the vortex penetration from the edges of the film, and on the contrary, the detecting mechanism of low-energy photons probably involves the vortex penetration from the film edges.
|
|
|
|
Korneev, A., Korneeva, Y., Manova, N., Larionov, P., Divochiy, A., Semenov, A., et al. (2013). Recent nanowire superconducting single-photon detector optimization for practical applications. IEEE Trans. Appl. Supercond., 23(3), 2201204 (1 to 4).
Abstract: In this paper, we present our approaches to the development of fiber-coupled superconducting single photon detectors with enhanced photon absorption. For such devices we have measured detection efficiency in wavelength range from 500 to 2000 nm. The best fiber coupled devices exhibit detection efficiency of 44.5% at 1310 nm wavelength and 35.5% at 1550 nm at 10 dark counts per second.
|
|
