光学 精密工程, 2018, 26 (10): 2407, 网络出版: 2018-12-26
Yb∶LuScO3晶体的超精密光学加工及其激光性能
Ultra-precision optical manufacture and laser performance of Yb∶LuScO3 crystal
光学加工 表面面形 表面粗糙度 树脂铜盘 optical manufacture Yb∶LuScO3 Yb∶LuScO3 surface profile surface roughness copper resin pad
摘要
Yb∶LuScO3晶体作为固体激光器的新型增益介质,其面形和表面质量严重影响激光器的光束质量,因此探索Yb∶LuScO3晶体的超精度光学加工工艺参数具有重要意义。本文系统开展了Yb∶LuScO3晶体超精密光学加工的工艺参数研究,针对Yb∶LuScO3晶体在加工过程中容易破裂和表面质量较差的问题,提出了拼接上盘和树脂铜盘抛光垫的关键技术。首先,使用COMSOL Multiphysics有限元软件对拼接工艺中选取的不同保护垫料的应力进行仿真。接着,研磨阶段逐步减小B4C磨料的粒径。然后,粗糙阶段使用树脂铜盘作为抛光垫,并对树脂铜盘抛光垫的作用进行了分析。最后,使用激光二极管泵浦加工好的样品进行激光输出实验。实验结果表明: 基于该技术加工后的晶体表面粗糙度RMS=0.296 nm,面形精度 PV=53 nm。在1 086 nm处获得了8.3 W的连续激光输出,斜效率为58%。该加工方法可以广泛应用于Yb∶LuScO3晶体的高精度加工。
Abstract
Yb: LuScO3 crystal is a new type of gain medium used in solid-state lasers. The surface profile and surface quality of the Yb: LuScO3 crystal affect the characteristics of the output laser beam significantly. Therefore, it is extremely important to explore the processing parameters for its ultraprecision optical manufacture. In this paper, a systematic study of the processing parameters for the optical manufacture of Yb: LuScO3 crystal was reported. To solve issues related to the brittleness of the Yb: LuScO3 crystal and the poor quality of the generated surface, the key technology of stitching and the use of copper resin pads were proposed. First, the stress due to different protective paddings was simulated using COMSOL Multiphysics software and the size of abrasive B4C particles was continually decreased during the stitching and lapping stages, respectively. Next, copper resin pads were used during the stage of rough polishing, and their function was explained. Finally, the output power of the continuous wave laser was achieved by diode-pumping the finely polished Yb: LuScO3 crystal. The results reveal a final surface roughness of 0.296 nm (root mean square value) and surface accuracy of 53 nm (peak-to-valley value). An output power of 8.3 W and a slope efficiency of 58% were obtained using a diode laser pump source at a wavelength of 1 086 nm. This method can be widely used for the high-precision machining of Yb: LuScO3 crystals.
沈冯峰, 徐学科, 高文兰, 于浩海, 张龙, 邵建达. Yb∶LuScO3晶体的超精密光学加工及其激光性能[J]. 光学 精密工程, 2018, 26(10): 2407. SHEN Feng-feng, XU Xue-ke, GAO Wen-lan, YU Hao-hai, ZHANG Long, SHAO Jian-da. Ultra-precision optical manufacture and laser performance of Yb∶LuScO3 crystal[J]. Optics and Precision Engineering, 2018, 26(10): 2407.