Semiconductor Laser Drive Source And Temperature Stabilization System

The semiconductor laser apparatus has two different modes of operation: One is the driving source for the laser to inject a constant current,and the temperature stabilization system is used to keep the laser working temperature stable.The other is that the driving source keeps the laser output power stable and the laser temperature is stable.This paper chooses constant current constant temperature working way.The system is based on the LC96 Butterfly semiconductor laser,according to the LC96 Butterfly Semiconductor laser Data manual can be defined the characteristics of the laser,pressure drop of 2.2V,the temperature change per degree Celsius will cause output peak wavelength of about 0.02 nm drift.Therefore,it is necessary to design a special driving source and temperature stabilization system for the laser.In this paper,the development process and the luminescence mechanism of the semiconductor laser are introduced,and then the driving source and the temperature stabilization system are developed according to the luminescence mechanism and working principle of the LC96 type laser.This article mainly divides into two parts:One: Design of the driving source of the LC96 type butterfly semiconductor laser.Based on the deep negative feedback principle and the SCS model of MOSFET,the driving source of LC96 type laser based on STM32 is built.The driving source includes the selection of the power supply chip,the analysis and the principle of deep negative feedback,the SCS model of MOSFET,the principle and analysis of the driving source,the protection module of the laser and the slow start module,and the PID algorithm.The high resolution current detection amplifier produced by ADI Company is used to AD8217 the output current and display the current value to the LCD screen through STM32 calculation.When the current value exceeds the Set alert value,the drive source is immediately stopped to achieve the purpose of protecting the laser.Second: The temperature stability system design of LC96 type butterfly semiconductor laser.Including temperature collection,PID adjustment compensation Circuit,TEC Drive.The temperature collection utilizes the LC96 type laser internal integrated thermistor and the partial voltage circuit,the ad gathers the thermistor both ends the voltage value to send the STM32 processing to display to the LCD.The TEC Drive uses the TEC special chip MAX1968 which the Maxin company produces.The chip is able to complete the two-way control of TEC heating and refrigeration,allowing independent setting of forward maximum current MAXIP and reverse maximum current maxin and maximum output voltage MAXV,thereby protecting the laser from overcurrent and overvoltage.The response of temperature stabilization system to temperature change is optimized and the time of laser reaching target temperature is reduced by using analog PID adjusting compensation circuit.Finally,using AD software to draw the principle diagram and circuit board of the driving source and temperature stabilization system.To manufacturers to make board and related circuit debugging and performance testing.The results are as follows: The semiconductor laser drive source system can output 0-950 ma current value,set the target current value through the key and start the driving source system,the output stability of two hours is 0.0024.Temperature stability control system in the 15?-25? range of semiconductor lasers to a good temperature stability,operating two-hour temperature stability of 0.0016.