大尺寸激光晶体是高功率全固体激光器的关键组成部分，然而晶体生长过程中不可避免会产生气泡、包裹物等缺陷，影响激光器性能。为了快速、有效地评价晶体缺陷，本文搭建了基于片状光束扫描的晶体缺陷三维成像系统。系统中利用鲍威尔棱镜对532 nm的点状激光进行整形以获取片状激光，通过远心镜头和CMOS探测器获取晶体缺陷产生的散射光，从而获取晶体缺陷的面分布情况，同时利用高精度位移平台进行面阵的逐一扫描，完成晶体的三维立体分布扫描。进一步结合数字图像处理技术，表征晶体缺陷的面分布特征，并重构晶体缺陷的体分布特征。基于上述系统对尺寸约为50 mm×50 mm × 100 mm的Yb∶YAG晶体内在缺陷进行测量，最小缺陷检测分辨率能够达到38。69 μm。本文为准确表征晶体的内在缺陷提供了新方法，同时也为晶体坯料的后期高精度加工提供了可视化的数据支撑。
Characterization Method for Internal Defects in Laser Crystals Based on Slice Beam Scanning
Large size laser crystals are a key component of high-power all solid-state lasers.However,during the crystal growth process,defects such as bubbles and inclusions are inevitably generated,which affect the performance of the laser.In order to quickly and effectively evaluate crystal defects,a three-dimensional imaging system for crystal defects based on sheet beam scanning was established in this paper.In the system,a Powell lens is used to shape a 532 nm point laser to obtain a sheet-like laser.The scattered light generated by crystal defects is obtained through a telecentric lens and CMOS detector to obtain the surface distribution of crystal defects.At the same time,high-precision displacement platforms are used to scan the surface array one by one,completing the three-dimensional distribution scanning of the crystal.Furthermore,combined with digital image processing technology,characterize the surface distribution characteristics of crystal defects and reconstruct the volume distribution characteristics of crystal defects.Based on the above system,intrinsic defects in Yb∶YAG crystals with dimensions of about 50 mm × 50 mm × 100 mm were measured with a minimum defect detection resolution of 38.69 μm.This article provides a new method for accurately characterizing the internal defects of crystals,and also provides visual data support for high-precision processing of crystal billets in the later stage.
万方数据
维普
