板条激光器的输出光束是具有大长宽比的矩形光束,其光束发散角在水平方向与竖直方向有较大差异。板条激光器输出光束含有的大量波前像差,极大地影响了其输出光束的光束质量。设计了一套针对板条激光器输出的1064nm的矩形像散光束的整形与像差补偿系统,该系统由3个球面柱面透镜与1个球面透镜组成,其中不同方向光焦度的柱面镜组合可以实现矩形光束在2个维度的整形扩束。从仿真中可以得到,通过改变光束整形与补偿系统内部的透镜间距,可以将人射的大小为15mm×1.5mm的矩形像散光束整形成为大小可在15mm×15mm~19mm×19mm之间变化的方形准直光束,且整形后的光束具有较高的光束质量。
The output beam of a slab laser is rectangular with high aspect ratio, and its divergence angles in horizontal and vertical directions are quite different. It contains large phase aberrations which greatly limit the beam qualities of slab lasers. A beam shaping and aberration compensation system is designed for a slab laser with the wavelength of 1064 nm in this paper. This system consists of 3 cylindrical and 1 spherical lenses. Cylindrical lenses are able to change the propagation of light in a particular direction, and the combination of two cylindrical lenses with different focal directions can achieve beam shaping in two dimensions. By changing the distance between the lenses, the rectangular beam can be shaped into square collimated beam, whose size varied in the range from 15 mm×15 mm to 19 mm× 19 mm with low phase aberrations, while the size of the input beam is 15 mm× 1.5 mm.