半导体激光器驱动电路设计及实验研究

Design and experiment of semiconductor laser drive control circuit

可调谐半导体激光器是可调谐二极管激光吸收光谱(TDLAS)系统的重要器件之一,激光器输出波长的稳定性直接决定系统测量的准确性和稳定性,而注入电流和工作温度是激光器输出波长的主要控制因素。设计了激光器驱动控制电路,并利用PID控制实现激光器工作温度的恒温控制,不仅能提供高精度低噪声的注入电流,而且对激光器有完备的安全保护功能。首先对注入电流和温度控制进行了短期测试分析,随后将设计的电路应用于中心波长为1512 nm的激光器,开展了测试分析,对激光器的温度、电流调谐特性进行研究,并对激光器输出波长的稳定性进行了短期和长期测试。结果发现激光器输出波长的标准偏差为0.0002,满足TDLAS系统对激光器恒流恒温控制的要求,表明该驱动控制电路实现了对半导体激光器的高精度驱动控制。

Tunable semiconductor laser is one of the most important devices in tunable diode laser absorption spectroscopy(TDLAS)system.The stability of the laser output wavelength directly determines the accuracy and stability of system measurements,and the laser output wavelength is mainly controlled by the injection current and operating temperature.A laser drive control circuit is designed,and PID control is utilized to implement thermostatic control of the laser operating temperature.The circuit can not only provide high-precision and low noise injection current,but also have a complete safety protection function for the laser.Firstly,the short-term test and analysis of the injection current and temperature control are carried out.Then,the designed circuit is applied to a laser with a central wavelength of 1512 nm,the temperature and current tuning characteristics of the laser are experimentally test and analyzed,and the stability of the laser output wavelength is tested in both short-term and long term.The standard deviation of the laser output wavelength is found to be 0.0002,which meets the requirements of TDLAS system for constant current and constant temperature control of laser,and indicates that the designed drive control circuit has realized the high-precision driving control of the semiconductor laser.