@InProceedings{Okunev_etal2008,
author="Okunev, O.
and Chulkova, G.
and Milostnaya, I.
and Antipov, A.
and Smirnov, K.
and Morozov, D.
and Korneev, A.
and Voronov, B.
and Gol{\textquoteright}tsman, G.
and Slysz, W.
and Wegrzecki, M.
and Bar, J.
and Grabiec, P.
and G{\'o}rska, M.
and Pearlman, A.
and Cross, A.
and Kitaygorsky, J.
and Sobolewski, R.",
editor="Sukhoivanov, I. A.
and Svich, V. A.
and Shmaliy, Y. S.",
title="Registration of infrared single photons by a two-channel receiver based on fiber-coupled superconducting single-photon detectors",
booktitle="Proc. SPIE",
year="2008",
publisher="SPIE",
volume="7009",
pages="70090V (1 to 8)",
optkeywords="SSPD; SNSPD; single-photon detectors; superconductors; superconducting nanost",
abstract="Single-photon detectors (SPDs) are the foundation of all quantum communications (QC) protocols. Among different classes of SPDs currently studied, NbN superconducting SPDs (SSPDs) are established as the best devices for ultrafast counting of single photons in the infrared (IR) wavelength range. The SSPDs are nanostructured, 100 {\^I}{\textonequarter}m$^{2}$ in total area, superconducting meanders, patterned by electron lithography in ultra-thin NbN films. Their operation has been explained within a phenomenological hot-electron photoresponse model. We present the design and performance of a novel, two-channel SPD receiver, based on two fiber-coupled NbN SSPDs. The receivers have been developed for fiber-based QC systems, operational at 1.3 {\^I}{\textonequarter}m and 1.55 {\^I}{\textonequarter}m telecommunication wavelengths. They operate in the temperature range from 4.2 K to 2 K, in which the NbN SSPDs exhibit their best performance. The receiver unit has been designed as a cryostat insert, placed inside a standard liquid-heliumstorage dewar. The input of the receiver consists of a pair of single-mode optical fibers, equipped with the standard FC connectors and kept at room temperature. Coupling between the SSPD and the fiber is achieved using a specially designed, precise micromechanical holder that places the fiber directly on top of the SSPD nanostructure. Our receivers achieve the quantum efficiency of up to 7{\%} for near-IR photons, with the coupling efficiency of about 30{\%}. The response time was measured to be < 1.5 ns and it was limited by our read-out electronics. The jitter of fiber-coupled SSPDs is < 35 ps and their dark-count rate is below 1s$^{-1}$. The presented performance parameters show that our single-photon receivers are fully applicable for quantum correlation-type QC systems, including practical quantum cryptography.",
optnote="exported from refbase (https://db.rplab.ru/refbase/show.php?record=1413), last updated on Sat, 15 May 2021 22:39:37 -0500",
doi="10.1117/12.793402",
opturl="https://doi.org/10.1117/12.793402"
}