激光诱导熔石英粒子喷溅动力学特征自动获取

Automatic acquisition of dynamic characteristics of fused silicon particle ejection induced by laser

粒子喷溅是熔石英后表面激光损伤过程的重要现象,其实验观测及动力学参数获取一直存在困难。为实现后表面损伤粒子喷溅动力学特征获取,搭建了时间分辨双帧阴影成像系统,并开发了基于分层Voronoi图和弹性势能模型的粒子识别与匹配算法。结合图像配准和去噪步骤,该方法能够克服双帧阴影成像技术固有的背景噪声严重和原点失配的缺点,在6μs及之后的延迟图像中能实现100%正确检测与匹配。与人工处理对比,该方法能以像素精度同时获取粒子的尺寸、速度大小及飞行方向,且数据处理时间缩短了约20倍。

Particle ejection is an important phenomenon in laser damage process of fused silicon exit surface,and it has been difficult to obtain the experimental observation and dynamic parameters. A time-resolved twoframe shadowgraphy system was built to acquire the dynamic characteristics of exit surface particle ejection. A particle recognition and matching algorithm based on layered Voronoi diagram and elastic potential model was developed. Combining the steps of image registration and denoising, this method can overcome the inherent shortcomings of serious background noise and mismatch of origin in two-frame shadowgraphy technology, and can achieve 100% correct detection and matching in the image of 6 μs delayed and later. Compared with manual processing, this method can simultaneously obtain the size, velocity and flight direction of particles with pixel accuracy, and the data processing time is reduced by about 20 times.