高功率半导体激光堆栈双波长合束及聚焦系统

针对两种波长的直接高功率半导体激光堆栈，为适应半导体激光在材料加工方面的需求，设计一种双波长合束及长焦距光学系统。首先，利用快慢轴准直镜对两种波长的激光堆栈进行初步准直，然后，用双波长合束镜将其合束。进而，利用倒置开普勒望远系统原理对慢轴光束进一步扩束准直，最终，用快慢轴聚焦镜实现同步聚焦。利用光参数积原理对聚焦系统进行理论分析，并根据瑞利长度公式计算出焦深。用ZEMAX软件对整个光路进行光线追迹，得出模拟结果。根据理论分析和软件模拟，开展相应实验。经合束和聚焦，实现焦距300 mm，焦点尺寸2.0 mm4.0 mm的聚焦光斑，输出功率5 000 W，功率密度达104瓦级。最后讨论该系统影响因素。聚焦光斑可用于激光熔覆，表面处理等工艺。

Double wavelength combination and focus system of high power laser diodes stack

A double wavelength combination and long focal length optical system was designed to combine and focus two direct high power laser diodes stacks with different wavelengths for laser material processing. First of all, the two LD stacks were collimated by fast and slow axis collimator respectively. Second, the two LD stacks were combined by double wavelength combine mirror. Then, the invert Kepler telescope system principle was applied to expand and collimate the laser beam in the slow axis direction. Finally, the fast and slow axis laser beams were focused at the same time. The focus optical system was analyzed by beam parameter product theory, and the focal depth was also be calculated by Rayleigh length formula. The whole optical path was simulated by ZEMAX software, and the simulation results were shown after ray tracing. Based on the theoretical analysis and ZEMAX simulation, the corresponding experiment were performed. After the combination and focusing, the focused spot size was 2.0 mm4.0 mm, and focal length was 300 mm. The final output power was 5 000 W and power density could reach to 104 W/cm2. The influence factors of this optical system were discussed finally. The focused spot can be applied to material processing, such as laser cladding and surface treatment.