Real-Time Laser Beam Quality Measurement Technique

提出一种新型光束质量实时测量技术, 该技术主要基于由平板反射镜组成的多平面成像系统, 一次性将激光束腰附近2倍瑞利距离内的多个光斑成像在同一个平面上, 用CCD相机获取这些光斑的光强分布图样。通过图像处理获知接收到的光斑的光强分布。采用远场发散角、焦点尺寸、桶中功率比和M2因子四种光束质量评价标准对激光光束质量进行评价。利用该方法实时测量了高能钕玻璃双板条激光器的输出光束。A new technique of real-time laser beam quality measurement is presented. It is based on a multiplane imaging method which consists of plate reflecting mirrors and enables simultaneous imaging of ten planes with various optical paths on a single charge coupled device (CCD) array. The maximum optical paths difference is approximately twice the Raleigh range. The intensities can be obtained by image processing. The beam quality is appraised by far-field divergence angle, focus spot size, M2 factor and power in the bucket separately. This method implements real-time measurement of the single-pulse high energy Nd:glass dual-slab laser beam quality successfully