键合Nd∶YAG/Cr4+∶YAG被动调Q微片激光器的优化设计

为了提高LD抽运脉冲微片激光器的输出性能和系统的集成度，采用龙格-库塔法对包含自发辐射与抽运速率的被动调Q速率方程进行了数值求解，结合被动调Q激光器输出参量的表达式对LD端面抽运的键合Nd∶YAG/Cr4+∶YAG微片激光器输出参量进行了数值仿真。结果表明，利用长度1mm/1.5mm的键合Nd∶YAG/Cr4+∶YAG晶体作为增益介质，当Cr4+∶YAG的初始透过率为75%、输出镜的透过率为30%、抽运光和腔内基模光半径均为100μm时，能够在抽运功率为4.5W的条件下实现平均功率0.7W、脉冲宽度174ps、重复频率16.1kHz的理论激光输出。该研究对被动调Q微片激光器的参量优化和应用具有理论指导意义。

Optimal design of composite Nd∶YAG/Cr4+∶YAG passive Q-switched microchip laser

Laser diode (LD) pumped passively Q-switched microchip laser has important applications in the field of industry, military, and medical treatment. To improve the output performance and system integration of LD pumped pulse microchip lasers, the Runge-Kutta method was used to solve the passively Q-switched laser rate equation, and the output parameters of LD end-pumped bonded Nd∶YAG/Cr4+∶YAG microchip laser was numerically simulated. The results show that with a 1mm/1.5mm bonded Nd∶YAG/Cr4+∶YAG as the gain medium, when the initial transmittance of Cr4+∶YAG is 75%, the transmittance of output mirror is 30%, and the radii of the pump and fundamental mode are 100μm, a 0.7W average power with pulse-width of 174ps at 16.1kHz can be obtained under the 4.5W pumping. This study has theoretical significance for the optimization and application of the passively Q-switched microchip laser.