Research On Power Technology Of Semiconductor Laser Temperature Control System

The rapid development of science and technology is leading the rapid development of military,medical,industrial production,optical fiber communication and other advanced technology fields.With its excellent characteristics,semiconductor lasers play an important role in these important fields.Because the driving power of the conductor laser is good or not,it directly determines the quality of the laser.In the process of laser operation,the direct and obvious influence on output is the stability of injection current and working temperature.Therefore,semiconductor laser driving power is of great importance for the development of a highly stable laser.Based on the analysis of the main reasons for the stability of the laser and the study of the principle and characteristics of the semiconductor laser,the technical performance index of the designed driving power supply is established on the basis of careful analysis of the factors that lead to the inaccurate stability of the laser.According to the technical index,the comparison is made.The design scheme is successfully implemented.The control mode of proportional integral based on closed loop control is the control idea of the temperature control part.In order to control the thermoelectric cooler effectively,the temperature of the laser should be collected through the thermistor,then the sampling value and temperature setting value are calculated.The difference of the two is used as the control signal to realize the automatic control of the temperature.System.This design uses the VMOS tube(full name V-groove metal-oxide semiconductor),or power field effect tube.As a power device,it designs the corresponding hardware circuit and software program,uses DSP to carry out real-time control,and finally determines the technical implementation of the main link of the power supply.In order to better realize the accurate control and make the output pulse current amplitude,pulse width and repetition frequency adjustable,the feedback control principle is adopted after reasoning and demonstration.In view of the powerful computing power of DSP(digital signal processing,Digital Signal Processing abbreviation)and its superior performance in simple and real-time control,the 32 bit fixed-point DSP,a powerful TMS320F2812,is introduced by TI company as a control software.A high precision,fast reaction and small volume is designed to make the semiconductor laser work at a fixed temperature,and the thermistor sampling measurement is combined with a semiconductor refrigerator(TEC)so that the semiconductor laser can work at a fixed temperature.The developed laser power supply can work steadily and reliably,which meets the requirement of high temperature requirement of LD,while the control system part and the power supply part can run well in real time.The output voltage of the designed power supply is continuously adjustable in the range of 0~50V,the maximum output current is 2A,and the ripple factor is less than 0.1%.