半导体激光列阵的高功率高亮度光纤耦合技术

High Power and High Brightness Fiber Coupling Technique for Laser Diode Arrays

设计了一种可同时实现高功率和高亮度激光输出的简单有效的光纤耦合技术。首先借助光纤列阵实现光束由线性排列到圆形排列的转换,从而有效提高半导体激光列阵输出光束的对称性;然后通过微透镜将光纤列阵输出的圆对称光束耦合进入一根较细的光纤,以进一步压缩光斑直径并提高光束亮度。基于几何光学的理论分析表明;在合适的参数条件下,直径为1.3 mm的光纤列阵输出光束与直径为0.4 mm的单根光纤的耦合效率可达90%以上,即在功率损耗低于10%情况下,激光束的亮度提高了近9倍。

A straightforward but effective fiber coupling technique for obtaining laser beams with both high power and high brightness is proposed. The principle of this technique is as follows., first linearly arranged beams are changed into circularly arranged beams by a fiber array so that the beam symmetry of a laser diode array can be greatly improved then the circular laser beam from the fiber array is coupled into a single thin fiber by a micro-lens to reduce the beam diameter and improve its brightness. Theoretical investigations based on the ray tracing method show that, with carefully chosen parameters, the laser beam of 1.3 mm in diameter from a fiber array can be coupled into a single fiber of 0.4 mm in diameter with efficiency higher than 90%, namely, the laser beam brightness is improved about 9 times with energy loss lower than 10%.