@Article{Korneeva_etal2021,
author="Korneeva, Y. P.
and Manova, N. N.
and Dryazgov, M. A.
and Simonov, N. O.
and Zolotov, P. I.
and Korneev, A. A.",
title="Influence of sheet resistance and strip width on the detection efficiency saturation in micron-wide superconducting strips and large-area meanders",
journal="Supercond. Sci. Technol.",
year="2021",
volume="34",
number="8",
pages="084001",
optkeywords="NbN SSPD; SMSPD",
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 $\mu$m. 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 $\mu$m when sheet resistance of the film is above 630$\Omega$/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{\texttimes}20$\mu$m2 to a circle 50 $\mu$m in diameter. In the latter case, the detector with the strip width of 0.49 $\mu$m 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.",
optnote="exported from refbase (https://db.rplab.ru/refbase/show.php?record=1793), last updated on Sat, 03 Jul 2021 17:26:25 -0500",
issn="0953-2048",
doi="10.1088/1361-6668/ac0950",
opturl="https://iopscience.iop.org/article/10.1088/1361-6668/ac0950",
opturl="https://doi.org/10.1088/1361-6668/ac0950"
}