高精度激光参数测量系统中衰减系统的研究与评价

 分析了楔形镜和中性玻璃衰减片组对光束的衰减原理，采用反射式楔形镜作为无像差定量衰减器，并同时使用中性玻璃衰减片组微调光束能量。实验测量了LD泵浦激光模式发生器基模和高阶模条件下激光束的M­²因子,结果表明：楔形镜反射式衰减器对光束质量无显著影响，将楔形镜第一次表面反射作为无像差定量衰减，入射角在0~55°范围内，单棱镜表面反射光束能量为入射光能量的4.3%，通过多块组合可以得到更大的衰减；可采用中性玻璃衰减片组对激光光束的衰减进行精细控制，使其满足CCD探测器动态范围要求。该结论可为高精度激光参数测量装置光衰减系统的研制提供理论依据。

Investigation and evaluation of cuneiform prism and neutral glass slices used as laser attenuator

The theories of cuneiform prism and series neutral glass slices used as laser attenuator are analyzed in this paper. An aberration-free laser quantitative attenuator made of cuneiform prism is adopted and a series of neutral attenuated slices are used for adjusting laser-beam enegy at the same time. The M2-factor of the Hermite-Gaussian beams generated by an LD-pumped mode master is measured and it has been verified that the cuneiform prism used as reflection laser attenuator of 4.3% 0<θi<55° has no distinct influence on the beam quality and the neutral glass slices have accurate adjusted the operation for laser beam energy. More powerful attenuator can be obtained by using the combination of multi-cuneiform prism. The precision control of the laser beam power was realized with neutral g