Optimal setting method for parameters of single-photon detector

Abstract

The invention discloses an optimal setting method for parameters of a single-photon detector, which comprises the steps of initializing the single-photon detector so as to set initial values of each parameter; performing optimization on the parameters one by one, enabling the rest of the parameters to be fixed when any one parameter is optimized, progressively increasing a value of the parameter according to a preset step until reaching the maximum value of the parameter, taking the corresponding initial value and the value after each time of progressive increase as intermediate values, as for each intermediate value, setting the corresponding parameter to be the intermediate value, detecting and acquiring a measurement array, calculating a signal-to-noise ratio corresponding to each intermediate value according to the measurement arrays of all of the intermediate values, and selecting the intermediate value corresponding to the maximum signal-to-noise ratio to act as an optimal value of the parameter. According to the invention, the posterior pulse probability can be effectively reduced by only optimizing the parameters of the single-photon detector, and the dead time of the single-photon detector can be shortened so as to enable the single-photon detector to be applicable to an OTDR (Optical Time Domain Reflectometry). In addition, a problem of long test time of the OTDR caused by the dead time of the single-photon detector is effectively solved.

Description

technical field [0001] The invention belongs to the technical field of photoelectric detection, in particular to a parameter optimization setting method of a single photon detector. Background technique [0002] The optical time domain reflectometer (OTDR) can be used for functional tests such as fiber attenuation, joint loss, and fiber fault location. It is an indispensable tool for the maintenance and construction of optical cable lines. The photodetector in the traditional OTDR works in linear mode, which has the advantage of fast measurement time. However, because the detection sensitivity is limited by its own thermal noise level, it cannot detect weak optical signals with only a dozen to thousands of photons , limiting the improvement of its measurement distance and accuracy. [0003] The application of single-photon detection technology can make up for the above shortcomings. This technology can detect extremely weak optical signals that are smaller than thermal nois...

AI Technical Summary

Problems solved by technology

[0010] 1) The dead time of the existing single-photon detection is usually long, reaching the us level, which leads to a very low repetition rate of the gate pulse and a long measurement time

Especially when applied to OTDR, compared with traditional OTDR, the required measurement time has been increased by several orders of magnitude, and a measurement often takes several hours, which limits the application

[0011] 2) The existing OTDR based on single-photon detection adopts all-optical sampling technology, frequency up-conversion technology, or these technologies are still in the research stage in China, and all require additional sampling lasers or pump lasers, which are costly and complex in structure and other issues, and did not propose to solve the problem of long measurement time

[0012] 3) The existing OTDR based on superconducting nanowire single photon detector (SNSPD) has almost no post-pulse effect, which can solve the problem of measurement time, but SNSPD works near absolute zero, which requires high refrigeration and requires an external cryogenic liquid Helium Dewar bottles or specially designed closed-cycle refrigerators are costly and bulky, and are not suitable for commercial applications

Images