Research And Implement Of Monitoring System For Superconducting Nanowire Single-photon Detector

As a new type of single-photon detector with high sensitivity,the detecting performance of superconducting nanowire single-photon detector(SNSPD)in the near-infrared waveband is obviously better than other types of single-photon detectors’.Therefore,the research on the basic theory and the practical application of SNSPD has become the research hotspot in the field of single-photon detection.By 2017,there are less than 10 research teams having independent research and development capability for SNSPD,and they focus on the development and improvement of the detector’s chip.Although great progress has been made,there are still many key problems to be solved.For example,a lot of misoperation occurs caused by the complexity of equipment operation and the lack of related knowledge in the process of using SNSPD.That reduces the working efficiency of SNSPD.In order to reduce misoperation caused by the complexity of equipment operation,the thesis proposes to research and develop a monitoring system for SNSPD.The monitoring system for SNSPD is characterized by simple operation,high degree of automation,display of full real-time information,and timely early warning for faults.The main research work of the thesis is as follows:1)Establishment of hardware platform.Firstly,the thesis introduces the structure,working principle and operating process of the manual operating system of SNSPD,and analyzes the shortage of the manual operating system.Secondly,a detailed demand analysis of the monitoring system is implemented,and the reasonable selection of the key equipments in the monitoring system is carried out.Finally,the power supply scheme and communication scheme are designed,and the hardware platform of the monitoring system is set up.2)Design and implementation of software.Firstly,the functions of software are analyzed and summarized according to the demand analysis.The software of system is divided into several function modules.And the interactive process between software modules and the interfaces between software and hardware are described graphically.Secondly,the specific coding implementation for the software is completed.Taking SQL Sever 2012 as a local database,the software is developed by Visual Studio 2012.And the program is written by C# language.Finally,with the function of real-time monitoring,the function of real-time data display and thefunction of fault early warning,the monitoring system for SNSPD is completed.And implementation of the function of fault early warning is based on the time series auto-regressive and moving average(ARMA)data prediction model.3)System testing.In order to test the performance of the monitoring system for SNSPD,the functional testing and the non-functional testing to the system are carried on,and the process and results of the testing are described in detail in this thesis.The functional testing includes the running testing of each function of the system,and the non-functional testing includes the stability and reliability testing for system,the response time testing for system and the security testing for system.The monitoring system for SNSPD completed in this thesis has passed the strict testing in the laboratory,and has been used in Research Institute of Superconductor Electronics of Nanjing University,Research Institute 38 of CETC and Yunnan Observatory of Chinese Academy of Sciences.The monitoring system for SNSPD runs well and meets the design requirements.As the result,the working efficiency of SNSPD is greatly improved.