Superconducting nanowire single-photon detector and preparation method thereof

Abstract

The invention belongs to the technical field of optical detection, and relates to a superconducting nanowire single-photon detector and a preparation method thereof. The superconducting nanowire single photon detector comprises a substrate; a reflecting layer which is positioned on the surface of the substrate; a detection layer which is located on the surface of the reflection layer and used fordetecting photons, and the detection layer comprises a plurality of superconducting nanowire units; and a matching layer which is at least located on the surface of the superconducting nanowire unit,wraps the superconducting nanowire unit and is at least used for reducing the polarization extinction ratio of the superconducting nanowire unit; by arranging the matching layer coating the superconducting nanowire unit in the superconducting nanowire single-photon detector, the polarization extinction ratio of the superconducting nanowire single-photon detector can be reduced by utilizing the matching layer, so that the polarization sensitivity of the superconducting nanowire single-photon detector is reduced, the application field of the superconducting nanowire single-photon detector is expanded. And the detection accuracy and repeatability are improved.

Description

technical field [0001] The invention belongs to the technical field of light detection, and relates to a superconducting nanowire single-photon detector and a preparation method thereof. Background technique [0002] Superconducting nanowire single-photon detectors (SNSPDs) are highly sensitive photodetectors that utilize photon absorption to excite non-equilibrium hotspots in superconducting nanowires for single-photon detection. Generally, it is made of ultra-thin (~5nm) ultra-fine (~100nm) superconducting material, which has the properties of high detection efficiency, low dark count, small time jitter and fast response rate. With the gradual deepening of people's understanding of SNSPD from mechanism to performance, the performance of SNSPD has been improved rapidly. Recent research results show that: in the near-infrared band, the performance of SNSPDs in all aspects is significantly better than other types of single-photon detectors. At present, the basic and applied...

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Problems solved by technology

[0005] The polarization sensitivity of SNSPD is not conducive to practical application

In the coherent light detection of conventional optical fiber links, the polarization direction of the incident light can be adjusted by an external polarization controller to achieve high-efficiency detection. In the case of incoherent light detection, the polarization state of photons is uncontrollable. Due to the different absorption efficiencies of SNSPDs for different polarization states of light, the detection efficiency of SNSPDs is limited by the absorption efficiency of TM polarization states of light, making SNSPDs unable to exert high detection efficiency. advantage, which is not conducive to the widespread application of SNSPD

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