对准位相匹配砷化镓（GaAs）晶体扩散键合制备方法进行了研究。采用超高真空预键合-高温退火方法，在不同载荷压力条件下，完成了三组准位相匹配GaAs倍频晶体的制备。准位相匹配结构的极化周期长度为219 μm，堆叠层数44层，直径18 mm，有效通光孔径达到15 mm，在通光面未镀膜条件下，最高的基频光与倍频光透射率在30%以上。以主脉冲宽度90 ns，拖尾宽度2~6 μs的横向激励大气压(TEA)-CO2激光器作为基频光光源，通过调谐基频光波长，在4.63~5.37 μm波段内得到了效率大于4%的倍频输出。当基频光波长为10.68 μm，主脉冲能量为409 mJ，晶体接收基频光功率密度达到3.65 MW/cm2时，得到了单脉冲能量26.9 mJ，峰值功率298 kW，倍频效率达到6.58%的倍频输出。

A diffusion bonding method of quasi-phase-matched (QPM)-GaAs crystal preparation is studied. By ultra-high vacuum pre-bonding-high temperature annealing method, the preparation of three quasi-phase-matched crystals is completed under different load pressures. The polarization period length of the QPM structure is 219 μm, number of layers is 44, the diameter is 18 mm, and the effective aperture is 15 mm. The best transmittance of the foundation and frequency doubling is above 30% without anti-reflection coating. Using transversely excited atmospheric pressure (TEA)-CO2 laser with 90 ns wide main pulse and 2~6 μs wide tailing as foundation source, we acquire second harmonic generaction (SHG) output with efficiency more than 4% on 4.63~5.37 μm waveband by tuning foundation wavelength. When the foundation wavelength is 10.68 μm, main pulse energy is 409 mJ, the density in QPM-GaAs is 3.65 MW/cm2, we get SHG output with 26.9 mJ pulse energy, 298 kW peak power, and the SHG efficiency of 6.58%.