Detecting Single Infrared Photons with 93 % System Efficiency

Published: February 25, 2013


Francesco F. Marsili, Varun B. Verma, Jeffrey A. Stern, Sean D. Harrington, Adriana E. Lita, Thomas Gerrits, Igor Vayshenker, Burm Baek, Matthew D. Shaw, Richard P. Mirin, Sae Woo Nam


Single-photon detectors (SPDs) are nonlinear transducers that respond to the absorption of one or more photons with an electrical signal1. 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 milestone experiments in a variety of fields such as quantum physics, astronomy, communications, biology, and chemistry. 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 fiber coupling loss, greater than 90% in the wavelength range λ = 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. Our SNSPDs outperform conventional SNSPDs by using a new material, amorphous tungsten silicide (WSi). WSi nanowires allow more degrees of freedom in optimizing the optical coupling to the detectors, are more robust to constrictions, and have a lower dark count rate than conventional devices. We expect fiber coupled WSi SNSPDs to find application in (1) fundamental tests of quantum mechanics, especially loophole-free Bell inequality measurements with photons ; (2) quantum information processing and communication; (3) time-tagged single photon counting; and (4) environmental monitoring.
Citation: Nature
Pub Type: Journals

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Created February 25, 2013, Updated February 19, 2017