高重频双波长复合干扰激光器设计

Design of dual-wavelength composite jamming laser with high-repetitive frequency

为解决基频光高重频与倍频光高平均功率之间的矛盾,设计了一台干扰用高重频双波长复合输出激光器。静态仿真了泵浦源效率、激光晶体受热和受力分布、激光高斯模式特征,得到了该激光器的复合输出特性。动态仿真调Q频率、倍频晶体长度对复合输出的影响以及分析倍频晶体热效应,发现在泵浦功率和谐振腔结构不变的前提下,需先满足基频光高重频工作,再优化倍频晶体长度和控制倍频晶体温度可提高倍频光的输出功率。按上述仿真结论开展的验证实验结果表明:当磷酸氧钛钾晶体长度为12 mm、输出镜透过率为10%、重复频率为50 k Hz时,设计的激光器基频光平均功率为18. 98 W,倍频光平均功率为2. 22 W,与仿真结论一致。

In order to solve the contradiction between high repetition rate of fundamental wave and high average power of second-harmonic wave,a new 1064 nm/532 nm dual-wavelength composite jamming laser with high-repetitive frequency was designed.The composite output characteristics of the laser were obtained by the static analysis of the pump source′s efficiency,heat and force distribution of crystal,and by the Gauss mode of laser.The influence on the dualwavelength composite output was analyzed by changing the Q-switching frequency,the length of the second harmonic generation crystal and by simulating the thermal effect of second harmonic generation crystal.It is found that the high frequency of fundamental wave should be satisfied first,and the output power of secondharmonic wave can be improved by optimizing the length of the second harmonic generation crystal and by controlling the temperature of second harmonic generation crystal under the condition of the constant pumping power and the structure of the resonator.The simulation conclusion was verified by an experiment.The experimental results show that when the length of KTiOPO4 crystal is chosen as 12 mm,the transmissivity of the output mirror is fixed to 10%,and the Q-switching frequency is selected as 50 kHz,the average output power of the fundamental wave is 18.98 W,and the average power of the output of secondharmonic wave is 2.22 W.