用于单频Tm∶YAG激光器稳频的精密温控系统

Temperature control system for frequency stabilization of single frequency Tm∶YAG laser

为满足2μm注入锁频激光器对单频种子光激光器中心频率稳定性要求,设计了基于数字PID自适应算法的精密温度控制系统。针对激光器温度变化不确定性的特点,系统采用非线性补偿、数字滤波、硬件隔离和器件选取等方法来提高温控精度。分析讨论了Γ、Kp、Ki、Kd等参数对系统敛散性的影响和调试方法,给出了温度变化时系统控制电压振荡收敛波形。将该系统应用于单频Tm∶YAG激光器中,6 min观察时间内激光器中心频率漂移约为19.776 MHz,频率稳定度约为1.31×10-7,满足2μm注入锁频激光器要求。实验结果证明,该系统工作稳定,抗干扰能力强,在10~35℃范围内温控精度约为±0.01℃。

A precise temperature control system based on adaptive digital proportion integration differentiation （PID） algorithm is presented to meet the requirement of 2 μm injected frequency-locked laser for frequency stabilization of the single frequency seed laser. According to the uncertainty of laser temperature variation, nonlinear compensation, digital filter, hardware isolator and component selection are used to guarantee the temperature control precision. On the basis of system design, the debug methods of F, Kp, Ki,K~ are discussed, and the oscillatory convergence waveforms of system control-voltage are measured. The system is applied to single frequency Tm ： YAG laser, the drift of laser fre- quency can be suppressed effectively. In observing time of 6 minutes, the offset of laser frequency is about 19. 776 MHz,the frequency stability is approximate 1.31 × 10-7, and meets the requirements of 2 μm injected frequency- locked laser. The experimental results show that good stability and strong anti-interference can be gained and the tem- perature-controlling error of the system is about ＋0. 01 ℃ at 10 -35 ℃.