@InProceedings{Milostnaya_etal2006,
author="Milostnaya, I.
and Korneev, A.
and Rubtsova, I.
and Seleznev, V.
and Minaeva, O.
and Chulkova, G.
and Okunev, O.
and Voronov, B.
and Smirnov, K.
and Gol{\textquoteright}tsman, G.
and Slysz, W.
and Wegrzecki, M.
and Guziewicz, M.
and Bar, J.
and Gorska, M.
and Pearlman, A.
and Kitaygorsky, J.
and Cross, A.
and Sobolewski, R.",
title="Superconducting single-photon detectors designed for operation at 1.55-{\textmu}m telecommunication wavelength",
booktitle="J. Phys.: Conf. Ser.",
year="2006",
volume="43",
pages="1334--1337",
optkeywords="NbN SSPD; SNSPD",
abstract="We report on our progress in development of superconducting single-photon detectors (SSPDs), specifically designed for secure high-speed quantum communications. The SSPDs consist of NbN-based meander nanostructures and operate at liquid helium temperatures. In general, our devices are capable of GHz-rate photon counting in a spectral range from visible light to mid-infrared. The device jitter is 18 ps and dark counts can reach negligibly small levels. The quantum efficiency (QE) of our best SSPDs for visible-light photons approaches a saturation level of {\textasciitilde}30-40{\%}, which is limited by the NbN film absorption. For the infrared range (1.55{\textmu}m), QE is {\textasciitilde}6{\%} at 4.2 K, but it can be significantly improved by reduction of the operation temperature to the 2-K level, when QE reaches {\textasciitilde}20{\%} for 1.55-{\textmu}m photons. In order to further enhance the SSPD efficiency at the wavelength of 1.55 {\textmu}m, we have integrated our detectors with optical cavities, aiming to increase the effective interaction of the photon with the superconducting meander and, therefore, increase the QE. A successful effort was made to fabricate an advanced SSPD structure with an optical microcavity optimized for absorption of 1.55 {\textmu}m photons. The design consisted of a quarter-wave dielectric layer, combined with a metallic mirror. Early tests performed on relatively low-QE devices integrated with microcavities, showed that the QE value at the resonator maximum (1.55-{\textmu}m wavelength) was of the factor 3-to-4 higher than that for a nonresonant SSPD. Independently, we have successfully coupled our SSPDs to single-mode optical fibers. The completed receivers, inserted into a liquid-helium transport dewar, reached {\textasciitilde}1{\%} system QE for 1.55 {\textmu}m photons. The SSPD receivers that are fiber-coupled and, simultaneously, integrated with resonators are expected to be the ultimate photon counters for optical quantum communications.",
optnote="exported from refbase (https://db.rplab.ru/refbase/show.php?record=1450), last updated on Sun, 16 May 2021 21:04:45 -0500",
issn="1742-6588",
doi="10.1088/1742-6596/43/1/326",
opturl="https://iopscience.iop.org/article/10.1088/1742-6596/43/1/326",
opturl="https://doi.org/10.1088/1742-6596/43/1/326"
}