在半导体激光器的光纤耦合系统中, bar条的各发光点指向偏差(偏向角)会恶化光束整形效果, 显著降低光纤耦合效率。针对该现象提出利用引入修正角的楔形整形镜补偿发光点的指向偏差, 改善激光束的指向性和光束整形效果。通过ZEMAX软件模拟与实验验证,在光纤耦合系统中使用引入修正角后的楔形整形镜片, 其整形效果显著改善, 测量的光束参数积(BPPs)在快轴和慢轴方向分别为7.25 mm·mrad和5.05 mm·mrad, 聚焦光斑为148 μm×135 μm(包含90%能量)。该系统将单个bar条耦合进芯径200 μm、数值孔径(NA)0.2的光纤中, 在注入电流60 A时, 获得稳定输出功率53 W, 对应电-光转换效率为47%, 光纤耦合效率为87%, 相对于使用修正前的楔形整形镜片, 光纤耦合效率提高了7%。

The wedge-shaped lens is the key and special optical component of the final optics assembly (FOA) in high power laser facility. The wedge-shaped lens wedge angle measurement plays a remarkable role in focusing performance of high power laser. If processing angle and work attitude of the wedge-shaped lens deviate from the specific work angle, big surface deviation will be introduced into the FOA. Special shape of the wedge-shaped lens is not conducive to the measurements of the transmission profile and wedge angle. A set of wedge-shaped lens measurement adjustment programmes is proposed, including measurement of the wedge-shaped lens in processing process, and off-line measurement of wedge-shaped lens during alignment and on-line measurement during the debugging process. The scheme can ensure the processing precision and working attitude of the wedge-shaped lens, guarantee the beam quality and the positioning accuracy of the FOA components of high power laser system.

楔形透镜是高功率激光系统终端光学组件的关键元件，也是较为特殊的光学元件，楔形透镜的楔角测量关系着高功率激光的聚焦性能。终端组件中楔形透镜的加工角度、工作姿态一旦偏离了特定的工作角度，终端组件会引入大的面形偏差，楔形透镜特殊的形状不利于楔形透镜面形、楔角的测量。提出了一整套楔形透镜测量调整方案，包括楔形透镜加工过程中的测量方案，楔形透镜安装过程中的离线测量与调整方案，以及终端组件上线调试过程中的在线调试测量方案。该套方案的实施能够保证楔形透镜的加工精度，及组件中楔形透镜能够工作在最佳工作姿态，保障了高功率激光系统终端组件的光束质量和定位精度。