采用旋转光栅法实现了声光调Q CO2激光器可调谐脉冲激光输出。理论分析了CO2激光波长调谐特性, 发现调节各支谱线腔内损耗是实现激光波长调谐的有效方法。进而理论计算了特定设计波长闪耀光栅的衍射效率与激光波长间的关系, 结果显示光栅调谐的激光谱线自准直角与光栅闪耀角一致时具有最高的衍射效率。采用闪耀角分别为31.97°(闪耀波长10.59 μm)和28.71°（闪耀波长9.60 μm）的光栅实验研究了声光调Q CO2激光器波长调谐特性, 分别获得了65条和75条激光谱线。实验结果显示: 光栅设计闪耀波长处于弱激光增益分支时可获得更多条激光谱线, 该实验与理论计算结果相符。在脉冲重复频率为1 kHz时, 获得10.59 μm激光脉冲宽度为160 ns, 平均功率4.2 W, 脉冲峰值功率26.25 kW, 且稳定性良好。

A tunable acousto-optic Q-switched CO2 laser was presented using a blazed grating. The tuning principle of CO2 laser was analyzed, and it was found that changing the intra-cavity loss of lines is an effective way to realize the laser wavelength tuning. Then the relationship between diffraction efficiency of blazed grating and the laser wavelength were researched. The theoretical calculations show that the grating has highest diffraction efficiency when the auto-collimating angle of laser line equals to blaze angle of grating. Two blazed gratings with blaze angle of 31.97° (blaze wavelength 10.59 μm) and 28.71°(blaze wavelength 9.60 μm) were employed and the tuning performances of acousto-optic Q-switched CO2 laser were researched on experiments. Laser emission lines of 65 and 75 were obtained separately. The emission lines were richer when blaze wavelength of grating equals to the laser wavelength with lower gain, which accorded with the theoretical calculations. When the repetition frequency is 1 kHz, the maximum average power of 4.2 W, pulse width of 160 ns, peak power of 26.25 kW are achieved at the wavelength of 10.59 μm, showing good stability.