Superconducting nanowire single photon detector based on deep silicon etching process and its preparation method

Abstract

The invention provides a superconducting nanowire single-photon detector based on a deep silicon etching process and a preparation method, which includes: an SOI substrate, including a back substrate, a buried oxide layer and a top layer of silicon from bottom to top; a first anti-reflection layer, located on the surface of the top silicon; the second anti-reflective layer, located on the surface of the back substrate; the deep groove, which penetrates the second anti-reflective layer, the back substrate and the buried oxide layer; the optical cavity structure, located on the first anti-reflective layer the surface; the superconducting nanowire is located between the first anti-reflection layer and the optical cavity structure; the reflector is located on the surface of the optical cavity structure. By etching deep grooves on the substrate, the distance between the coupling fiber and the device is shortened, which avoids the use of long focusing lenses in traditional back-coupling structure superconducting nanowire single-photon detection devices and facilitates the alignment of the fiber MU head and the device. Coupling; avoids the problem of long-distance focusing in the optical cavity structure and the impact of the substrate Fabry-Perot cavity on the absorption efficiency, has higher absorption efficiency for the target wavelength, and improves the device detection efficiency.

Description

technical field [0001] The invention belongs to the technical field of light detection, and relates to a superconducting nanowire single-photon detector, in particular to a superconducting nanowire single-photon detector based on a deep silicon etching process and a preparation method thereof. Background technique [0002] Superconducting Nanowire Single Photon Detector (SNSPD) is a new type of single photon detection device developed in recent years, which can realize high-efficiency single photon detection from visible light to near infrared. Due to its advantages such as high quantum efficiency, low dark count, high detection rate, and low time jitter, SNSPD has been rapidly applied in applications such as quantum information technology, laser communication, satellite-to-earth ranging, bioluminescent detection, and depth imaging. [0003] SNSPD mainly uses low-temperature superconducting ultra-thin film materials, such as NbN, Nb, NbTiN, WSi, etc. The typical thickness i...

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Problems solved by technology

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a superconducting nanowire single photon detector based on deep silicon etching process and its preparation method, which is used to solve the problem of superconducting nanowire single photon detection in the prior art. The absorption efficiency of the detector is low, in order to solve the long-distance focusing of the back light to the NbN nanowire, a special long-focus lens is required, and the influence of the substrate Fabry-Perot cavity on the absorption efficiency, etc.

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