Method and device for reducing non-intrinsic dark count of superconducting nanowire single photon detector

Abstract

The invention provides a method and device for reducing the non-intrinsic dark count of a superconducting nanowire single photon detector. The method comprises the step that a short wave pass multi-layer thin-film filter is integrated on the superconducting nanowire single photon detector, wherein the short wave pass multi-layer thin-film filter is a device with the short wave pass filtering function and is implemented through multiple layers of dielectric film. The non-intrinsic dark count is the dark count triggered by optical fiber black-body radiation and stray light in the outside world. According to the method and device, operation is easy, and non-signal-radiation is filtered out just by integrating the short wave pass multi-layer thin-film filter on a substrate. According to the method, the non-intrinsic dark count can be effectively reduced while signal radiation and optical coupling efficiency of the device are ensured, and therefore detection efficiency of the device under the specific dark count condition is improved; in addition, only optical waves with the wavelength larger than 1550 nm need to be filtered out, the design requirement is reduced, and the filter can be easily implemented.

Description

technical field [0001] The invention belongs to the technical field of light detection, and in particular relates to a method and a device for reducing the extrinsic dark count of a superconducting nanowire single photon detection device. Background technique [0002] Superconducting Nanowire Single Photon Detector (SNSPD) is an important photon detector, which can realize single photon detection from visible light to infrared band. SNSPD mainly uses low-temperature superconducting ultra-thin film materials, such as NbN, Nb, TaN, NbTiN, WSi, etc. The typical thickness is about 5-10nm, and the device usually adopts a meandering nanowire structure with a width of about 100nm. The structure of an existing superconducting nanowire single photon detection device is as follows: figure 1 As shown, it includes substrates 20-40 with anti-reflection layers on both upper and lower surfaces, an optical cavity structure 50, superconducting nanowires 60, and reflective mirrors 70, etc. ...

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Problems solved by technology

[0006] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method and device for reducing the extrinsic dark count of superconducting nanowire single-photon detection devices, which is used to solve the problems caused by the extrinsic dark count in the prior art. And lead to the degradation of the performance of nanowire single photon detection devices or solve the problem that the current filter design is too complicated

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