Detecting Single Infrared Photons with 93% System Efficiency
  Single-photon detectors (SPDs) at near infrared wavelengths with high system detection efficiency (> 90%), low dark count rate (< 1 counts per second, cps), low timing jitter (< 100 ps), and short reset time (< 100 ns) would enable landmark experiments in a variety of fields. Although some of the existing approaches to single-photon detection fulfill one or two of the above specifications, to date no detector has met all of the specifications simultaneously. Here we report on a fiber-coupled single-photon-detection system employing superconducting nanowire single photon detectors (SNSPDs) that closely approaches the ideal performance of SPDs. Our detector system has a system detection efficiency (SDE), including optical coupling losses, greater than 90% in the wavelength range \lambda = 1520-1610 nm; device dark count rate (measured with the device shielded from room-temperature blackbody radiation) of ~ 0.01 cps; timing jitter of ~ 150 ps FWHM; and reset time of 40 ns. 
F. Marsili, V. B. Verma, J. A. Stern, S. Harrington, A. E. Lita, T.   Gerrits, I. Vayshenker, B. Baek, M. D. Shaw, R. P. Mir...
physics.optics cond-mat.supr-con quant-ph