Dark Count Suppression in Superconducting Nanowire Single Photon Detectors

One of the important performance parameters of superconducting nanowire single photon detectors (SNSPD) is the dark count rate. Dark counts are related to thermally-activated hopping of magnetic vortices across the nanowire. We present an experimental analysis of how the thermal coupling of the NbN SNSPD to the heat sink affects the dark count rate. It was found that the rate decreases with the increase in coupling strength while the detection efficiency remains almost constant.