Method and detector for reducing extrinsic dark count in nanowire single photon detectors

摘要

Provided are a method and device for reducing the extrinsic dark count of a superconducting nanowire single photon detector (SNSPD), comprising the steps of: integrating a multi-layer film filter on the superconducting nanowire single photon detector; wherein, the multi-layer film filter is a device implemented by a multi-layer dielectric film and having a band-pass filtering function. The extrinsic dark count is the dark count triggered by optical fiber blackbody radiance and external stray light. The superconducting nanowire single photon detector comprises: a substrate having an upper surface integrated with an upper anti-reflection layer and a lower surface integrated with a lower anti-reflection layer; an optical cavity structure; a superconducting nanowire; and a reflector. The present invention is easy to operate, and only needs to integrate the multi-layer film filter on the substrate of the SNSPD to filter non-signal radiation. The method effectively reduces the extrinsic dark count while ensuring the signal radiation and the optical coupling efficiency of a device, thereby improving the detection efficiency of the device in dark count specific conditions.