%0 Conference Proceedings
%T Superconducting single-photon detectors for GHz-rate free-space quantum communications
%A Verevkin, A. A.
%A Zhang, J.
%A Slysz, W.
%A Sobolewski, R.
%A Lipatov, A. P.
%A Okunev, O.
%A Chulkova, G.
%A Korneev, A.
%A Gol’tsman, G. N.
%Y Ricklin, J. C.
%Y Voelz, D. G.
%S Proc. SPIE
%D 2002
%V 4821
%I SPIE
%F Verevkin_etal2002
%O exported from refbase (https://db.rplab.ru/refbase/show.php?record=1523), last updated on Thu, 20 May 2021 22:22:15 -0500
%X We report our studies on the performance of new NbN ultrathin-film superconducting single-photon detectors (SSPDs). Our SSPDs exhibit experimentally measured quantum efficiencies from   5% at wavelength λ = 1550 nm up to  10% at λ = 405 nm, with exponential, activation-energy-type spectral sensitivity dependence in the 0.4-μm - 3-μm wavelength range. Using a variable optical delay setup, we have shown that our NbN SSPDs can resolve optical photons with a counting rate up to 10 GHz, presently limited by the read-out electronics. The measured device jitter was below 35 ps under optimum biasing conditions. The extremely high photon counting rate, together with relatively high (especially for λ > 1 μm) quantum efficiency, low jitter, and very low dark counts, make NbN SSPDs very promising for free-space communications and quantum cryptography.
%K NbN SSPD
%K SNSPD
%K single-photon detector
%K thin-film superconductivity
%K quantum cryptography
%K ultrafast communications
%R 10.1117/12.453542
%U https://doi.org/10.1117/12.453542
%P 447-454