作为干涉测量系统的光源,半导体激光器的工作状态受温度的影响比较大。当外界的温度发生改变时,激光器的输出波长会发生改变,出现了干涉条纹不清晰的现象,大大影响了干涉测量。因此温度的控制对干涉的测量显得尤为重要。对半导体激光器的温度进行精密控制,是半导体激光器在实际应用中首要考虑的问题。本文利用利用RC滤波电路和热敏电阻提出了一种不同于常规电桥处理的方法,即基于相差识别的温度传感原理,对半导体激光器的温度实时控制。利用二阶滤波电路产生了高稳定度的信号源,基于QuartusⅡ开发平台利用VerilogHDL设计了计数模块。负温度系数的热敏电阻器作为温度测量器件,并和激光器以及TEC组合在一起。半导体制冷器TEC作为控温执行元件,设计了对半导体激光器进行控制的温度装置,提高干涉条纹的质量。实验表明,不管是升温控制还是降温控制,系统控制的响应速度比较快,温度被控制在一定温度下,干涉条纹信号稳定。该系统的温度稳定精度达到0.01℃。
As the optical source of the interference measurement system,the semiconductor laser working condition has been influenced seriously by the temperature. When the outside temperature changes, the output wavelength of the semiconductor laser is changed, and the interference fringes come to be un- clear, which greatly affects the interferometry. So the temperature control is important to the interfero- metric measurement. This paper,by using RC filter circuit and thermistor, proposes a different tempera- ture detection method based on phase recognition to control laser temperature real-timely from the cony- entiional bridge. The second order filtering circuit is used to produce the high stability signal source and Verilog HDL is used to design counting module based on Quartus II development platform. The negative temperature coefficient (NTC) thermistor is used as temperature measurement device and the semicon- ductor thermoelectric cooler (TEC) is used as temperature control actuator to design a temperature con trol device for semiconductor lasers to improve the quality of the interference fringes. The experimental results show that whether heating control or cooling control, the system control response speed is faster, the temperature is controlled at a certain level, and the temperature stability accuracy of the system can be 0.01℃.