涡旋光束通过非高斯随机粗糙面的场分布特性

基于角谱衍射理论,利用Johnson传递系统数值模拟非高斯粗糙面,研究了拉盖尔-高斯涡旋光束通过随机非高斯粗糙表面的场分布特性。在分析了非高斯粗糙面方向自相关长度、峰度、偏斜以及均方根粗糙度对涡旋光束场分布影响的基础上,研究了涡旋光束通过随机粗糙表面后光束光强分布变化时的均方根粗糙度取值范围,并通过实验,将实验数据与仿真结果进行了对比分析。结果表明:当非高斯粗糙面方向相关长度为20 mm,偏斜为0.001,峰度为6,均方根粗糙度大于0.12 mm时,拉盖尔-高斯光束透过随机表面的光强分布不再保持空心分布,对应的相位奇点消失。

Field distribution characteristics of vortex beams passing through the non-Gaussian random rough surface

Based on the theory of angular spectrum representation, the non-Gaussian rough surface is simulated by Johnson transfer system, and the field distribution characteristics of Laguerre-Gaussian vortex beams passing through the random non-Gaussian rough surface are studied. The effects of the direction correlation length, kurtosis, skewness and root mean square roughness of non-Gaussian rough surface on the field distribution of the vortex beam are analyzed. The range of the root mean square roughness is studied when the intensity distribution of the vortex beam passing through the random rough surface changes, and the corresponding experiment is carried out. The experimental data are compared with the simulation results. The results show that when the direction correlation length of non-Gaussian rough surface is 20 mm, the skewness is 0.001, the kurtosis is 6, and the root mean square roughness is more than 0.12 mm, the intensity distribution of the Laguerre-Gaussian beam passing through the random surface no longer keeps the hollow distribution, and the corresponding phase singularity disappears.