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

摘要

The present invention includes a step of providing a multilayer filter on the superconducting nanowire single photon detector, wherein the multilayer filter is a device having a filtering function realized by a multilayer dielectric film. Methods and detectors are provided for reducing extrinsic dark counts in photon detectors. The extrinsic dark count is a dark count that is triggered by the black body radiation of the optical fiber and external stray light. The superconducting nanowire single-photon detector includes a substrate having an upper antireflection layer and a lower antireflection layer coupled to upper and lower surfaces, an optical cavity structure, a superconducting nanowire, and a reflection mirror. The present invention is simple to operate and non-signal radiation is filtered simply by providing a multilayer filter on the substrate of a superconducting nanowire single photon detector (SNSPD). The method guarantees signal coupling and detector optical coupling efficiency, and can effectively reduce the extrinsic dark count, thereby increasing the detection efficiency of the detector under certain dark count conditions. Become. [Selection] Figure 2