温度是影响半导体激光器性能指标之一,为了实现快速稳定的温度控制,研究了系统的温度控制硬件和算法。系统以MSP430低功耗微控制处理器为核心,采用自动调节制冷片电压和脉冲宽度调制(PWM)输出脉冲方式相结合的驱动电路,根据系统的机械控制热平衡模型和装置的高低温实验建立了自适应温度调节算法。经过高低温实验研究,从-40~50℃控制到温度为23℃时,激光器温度稳定所消耗的时间分别为2 min 30 s和1 min 30 s,其中控制精度为0.2℃。对激光器功率稳定性进行实验分析,控温前后激光功率的稳定性,从5%提高到1%以内,满足人眼安全对激光功率密度的要求,该方案的设计对于小功率、快速稳定的激光系统的设计具有可借鉴意义。
Temperature was one of the parameters influencing the characteristic of the semiconductor laser.To realize the temperature control quickly and stably,the temperature controlling hardware and algorithm were researched. The system was based on the Micro Control Unit(MCU) MSP430. The driver circuit was used, adjusting circuit voltage adaptively was in conjunction with output style of pulse width modulation.The self-adjusting temperature algorithm was also designed by the model of the mechanical temperature balance and experiment in high-low temperature test-box. According to the experiment result, the stability time from the temperature-40-+50 ℃ to the setting temperature 23 ℃ were respectively 2 min 30 s and1 min 30 s, respectively. The control precise was 0.2 ℃. By the analysis of power stability experiment result,the laser power stability is improved from 5% before temperature control to less than 1% after temperature control. The laser power stability density is safe for the eye. The schematic design of system has significance for the small power and quick stability laser system.