外腔式SrWO4拉曼激光器的输出特性研究

研究了外腔式SrWO4拉曼激光器在ns脉冲抽运下的输出特性。利用主动调Q的Nd∶YAG激光器产生的脉冲宽度为11.7 ns,输出能量为80 mJ的激光作为抽运源,拉曼激光谐振腔采用平平腔,实验采用4片对一阶斯托克斯脉冲和二阶斯托克斯脉冲不同反射率的输出耦合镜,测量了输出能量与抽运能量的关系,计算了转换效率与抽运能量的关系。当输出耦合镜对一阶斯托克斯脉冲的反射率为39.9%时,实验得到一阶斯托克斯脉冲的最大能量和转换效率分别为23.9 mJ和36.2%,当输出耦合镜对一阶斯托克斯脉冲和二阶斯托克斯脉冲的反射率分别为80.5%和12.4%时,得到二阶斯托克斯脉冲的最大输出能量和转换效率分别为16.4 mJ和25.4%,典型的一阶斯托克斯脉冲和二阶斯托克斯脉冲的脉冲宽度分别为6.1 ns和5.8 ns。

Output Properties of External Resonator SrWO4 Raman Laser

The output properties of an external resonator SrWO4 Raman laser pumped by nanosecond pulses are studied. An actively Q-switched Nd∶YAG laser is used as the pumping source, with pulse width of 11.7 ns and energy of 80 mJ. The Raman laser cavity is a flat-flat one. Four output couplers with different reflectivities for the first- and second-Stokes wavelengths are used in the experiment. The relations between the output energy and pumping energy are measured, and the relations between the conversion efficiency and pumping energy are calculated. When the output coupler reflectivity for the first-Stokes wavelength is 39.9％, the obtained maximum output energy and conversion efficiency of the first-Stokes pulses are 23.9 mJ and 36.2%, respectively. When the output coupler reflectivities for the first and the second-Stokes wavelengths are 80.5％ and 12.4％, respectively, the obtained maximum output energy and conversion efficiency of the second-Stokes pulses are 16.4 mJ and 25.4%, respectively. The pulse widths of the typical first and second-Stokes pulses are 6.1 ns and 5.8 ns, respectively.