以半导体侧泵钇铝石榴石激光器为泵浦源, 采用腔内泵浦两块三硼酸铯晶体, 产生满足高功率与高光束质量要求的三倍频355 nm紫外激光.通过使用法拉第旋转器谐振腔优化设计与热效应补偿提高输出光的光束质量, 并且使用体光栅作为输出镜, 在实现线宽窄化同时保持准相位匹配的高效性能.该光刻用紫外激光源成功地替代准分子激光器, 使用在一套大面积亚纳米级投影式光刻系统上, 工作时紫外光输出功率为4.37 W, 光束质量因子为2.27.

An intracavity frequencytripling of a diodeedgepumped passively Qswitched 1 064 nm Nd∶YAG laser is presented to generate high power 355 nm UV laser. Several essential technologies are put forward to achieve the best beam quality such as a volume grating to maintain quasi phase matching with narrow linewidth, optimization and thermal effects compensation for cavity. The task first takes advantage of volume grating and two CBO crystals as SHG and THG nonlinear optical conversion material to obtain high UV laser power output more than 4 W, light quality factor M2<2.5, meanwhile it is the first time to realize thermal effect using 45° Faraday rotator. The achievement is expected to be the popular light source system in lithography instead of conventional excimer laser.