中红外激光准相位匹配GaAs晶体的制备工艺

Fabrication and characteristics of quasi-phase-matched GaAs crystal for mid-infrared laser

极化方向周期排列的GaAs通过准相位匹配方式能够实现高功率CO2激光器倍频,利用晶片键合技术对GaAs极化方向反转堆叠的制备工艺和键合性能进行研究,采用氢离子轰击的方法去除GaAs表面氧化物,提高光学性能,超高真空中预键合减少界面微气孔密度,退火处理增加键合力,实现了双层GaAs的可靠键合,两层GaAs成为一块单晶结构的整体,利用键合技术获得了大通光孔径、低光学损耗的周期性结构GaAs晶体,为实现高功率CO2激光器倍频提供了途径。

A periodic structure of bonded GaAs wafers can be used for high power quasi-phase-matched second-harmonic generation of a CO2 laser . The fabrication of the QPM GaAs based on wafer bonding technology and interfacial properties of this crystal were studied . Hydrogen ion beam was used to remove the oxide layer on the GaAs surface to improve its optical properties . Pre-bonding process in the ultra-high vacuum reduced the microspores density of the bonding interface . Heat treatment increased the bonding force . Thus a reliable bond of the two-layer GaAs was realized . The two-layer GaAs combined into a single crystal structure without amorphous layer formed by oxide . By this bonding process a periodic polarization reversed GaAs crystal with large aperture , low loss was obtained , therefore providing a way for realizing high power frequency doubling of CO2 laser using quasi-phase-matching technology .