PT Unknown AU Moshkova, MA Morozov, PV Antipov, AV Vakhtomin, YB Smirnov, KV TI High-efficiency multi-element superconducting single-photon detector SE Proc. SPIE PY 2021 BP 2 EP 8 VL 11771 DI 10.1117/12.2589157 DE PNR SSPD; large active area; detection efficiency AB We present the result of the creation and investigation of the multi-element superconducting single photon detectors, which can recognize the number of photons (up to six) in a short pulse of the radiation at telecommunication wavelengths range. The best receivers coupled with single-mode fiber have the system quantum efficiency of ⁓85%. The receivers have a 100 ps time resolution and a few nanoseconds dead time that allows them to operate at megahertz counting rate. Implementation of the multi-element architecture for creation of the superconducting single photon detectors with increased sensitive area allows to create the high efficiency receivers coupled with multi-mode fibers and with preserving of the all advantages of superconducting photon counters. ER