提高半导体激光二极管功率密度的光束整形方法

针对半导体激光二极管由束散角大（14~46）导致的激光功率密度在传播过程中不断衰减的问题，提出了一种提高激光功率密度的光束整形方法。首先以X型柱面平凸透镜和Y型柱面平凸透镜对激光二极管输出光束慢轴和快轴方向进行准直，然后通过一对平凸透镜组合进行扩束，进一步提高光束平行度，最后由单片平凸透镜将光束聚焦为高功率密度的光点。采用Light Tools软件仿真光路、优化光学元件参数，对光学元件进行实际选型后安装并调试光束整形系统。测试结果表明:半导体激光二极管输出光束的67%激光能量汇聚于直径1 mm圆内，激光功率密度优于30 W/cm2。

Beam shaping method to improve power density of semiconductor laser diodes

To solve the problem that the power density of laser beam attenuated along the propagation direction, which was caused by large beam divergence angle (14-46) of semiconductor laser diode, a beam shaping optical system to improve power density was proposed. An X type planoconvex cylindrical lens and a Y type planoconvex cylindrical lens were selected to collimate the laser beam. Then, a pair of planoconvex spherical lenses were applied to improve the parallelism. Finally, a single planoconvex spherical lens focused the laser beam to a spot with high power density. The lenses were chosen and optimized through Light Tools simulation. A real beam shaping optical system was mounted and built. Test results show that 67% laser power is converged into a cycle with diameter of 1 mm, and the power density is over 30 W/cm2.