Study On The Effect Of Millisecond Pulsed Laser On The Electrical Parameters Of Silicon-Based Four-Quadrant Detectors

Silicon-based QPD detectors have a wide range of applications in real life.They are an important part of laser guidance,laser collimation,and laser spot detection systems.It is prescribed in applications that are multifunctioning on account of laser irradiation.This application of QPD has caused a great impact such as laser irradiation causes damage,and the true electrical feedback cannot be attained.Therefore,studying the electrical parameters of the interaction between the millisecond pulse laser and the silicon-based QPD detector is of instructive significance for the development of silicon-based QPD detector protection and anti-interference applications.In this dissertation,the temperature,output current,target detection positioning,and the dark current of the millisecond pulse laser and silicon-based QPD are explored through theory,simulation,and experiment.According to theoretical aspects,the thermal and electrical models of the interface between the millisecond pulse laser and the silicon-based QPD detector in single quadrant are explored.When the external bias voltage is 40 V,the thermal model of the interface between the millisecond pulse laser and the silicon-based-QPD detector realizes the theoretical analysis of the temperature evolution of the silicon-based QPD detector irradiated by the laser.The output current model,target detection,positioning model and dark current model are established respectively to comprehend the theoretical analysis of output current,target detection,location and dark current of silicon-based QPD irradiated by laser.According to simulation aspects,based on the theoretical model,a thermal simulation model,the output current simulation model,the target detection positioning simulation model,and the dark current simulation model was determined.The thermal simulation model simulates the evolution of the temperature at the laser action point.The electrical simulation model simulates the output current of the four quadrants when the millisecond pulse laser interacts with the single quadrant of the silicon-based QPD detector.Target detection and positioning simulation analyze the influence of laser spot properties on positioning through calculation.The dark current simulation model simulates the dark current at different bias voltages.According to experimental work,the experimental platform for a millisecond pulsed laser and a silicon-based QPD detector was developed,and experimental studies on temperature rise,output current,and dark current were carried out.Through experiments,the relationship between the temperature,output current,and dark current of the laser spot on the upper surface of the silicon-based QPD detector with the laser energy density and pulse width was obtained.The experimentally calculated results are all highly consistent with the theoretical and simulation models.The experimental analysis focuses on the influence of the single quadrant current on the output current of other quadrants,the relaxation of electric current after the laser action,and the influence on the positioning results of the QPD detector.