Superconducting single-photon detector and package method

Abstract

The invention discloses a superconducting single-photon detector, which comprises a chip fixing platform, an optical fiber fixing platform and a beam-focusing system. The invention also discloses a package method based on the superconducting single-photon detector, which comprises the following steps: (a) aligning a detection area of a chip with an intermediate small hole of the chip fixing platform; (b) fixing a fiber pigtail and inputting a visible reference beam through another interface of the optical fiber; and (c) by observing an optical system, finely tuning the position between a beamoutlet of the optical fiber and the detection area of the chip to fix the optical fiber fixing platform and the chip fixing platform. The single-photon detector can work at a temperature of between 1.8 and 300K, and the alignment of beams and components are not influenced by the increase and the reduction of temperature. A detector packaged by the superconducting single-photon detector and the method has high photon coupling efficiency, stable work and high reliability and can be used for measuring for a plurality of times with good repeatability.

Description

technical field [0001] The invention relates to a single photon detector, in particular to a superconducting single photon detector. In addition, the invention also relates to a packaging method based on the superconducting single photon detector. Background technique [0002] When the superconducting thin film is well below the critical temperature, the superconductor is in the superconducting state. At this time, if a current is passed through the film, when the current is higher than a certain value, the superconducting state will be destroyed and transformed into a normal state. This current is called the critical current, and the current passing through the unit cross-section becomes critical current density. If the superconducting thin film is processed into nano-strips, placed in an environment far below its critical temperature, and a current slightly lower than the critical current is applied, the superconducting nano-strips are very sensitive to incident photons....

AI Technical Summary

Problems solved by technology

At the same time, the detection area of ​​superconducting single photon detectors is very limited, usually less than 20 microns × 20 microns (if the detection area is too large, the repetition rate will be greatly reduced due to the dynamic inductance of the superconducting material itself). It is very difficult to couple photons onto such a small area

Secondly, the disassembly and operation of the superconducting single photon detector are at room temperature and liquid helium temperature respectively, so multiple measurements will heat up and cool down, the alignment of optical coupling, impedance matching, etc. are easily damaged, and the photon coupling efficiency is low

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