金属随机粗糙表面的散射光偏振特性的实验研究

Experimental study of polarization properties of scattering light from metal random rough surfaces

为了讨论随机粗糙表面的散射偏振特性随入射条件以及自身表面特征的变化规律,基于斯托克斯-穆勒矩阵变换方法设计搭建了主动偏振光照明的全偏振成像系统,入射光偏振态分别为线偏振光和圆偏振光,在不同入射角度下,对8种不同粗糙度的镍合金表面的散射偏振特性进行了测量,分析了不同成像条件下该金属目标的散射光偏振特性的差异。实验结果表明:同一粗糙表面对圆偏振光的退偏振效应强于线偏振光;圆偏振光入射时,散射光偏振角对入射角和表面粗糙度相比于线偏振光入射时更敏感;另外,目标表面的退偏振效应随着表面粗糙度和入射角的增大而增大。当粗糙度较小时,目标表面的退偏振程度随入射角增大而显著增大;当表面粗糙度增大,该变化趋势逐渐减缓。

In order to discuss the variation of polarization characteristics of scattering light from random rough surface with different incident conditions and surface characteristics, a full active polarization imaging system was designed based on Stokes-Muller matrix transformation method. The scatte-ring polarization characteristics of eight different roughness nickel alloy surfaces were measured with linearly polarized light or circularly polarized light in different incident angle. And the polarization characteristics of the scattering light from the metal targets were analyzed. The experimental results show that the depolarization of the same rough surface on circularly polarized light is stronger than that of linearly polarized light, and that when the circularly polarized light is incident, the angle of polarization of the scattered light is more sensitive to the incident angle and surface roughness than when linearly polarized light is incident. The depolarization of the target surface increases with the increase of surface roughness and angle of incidence. When the roughness is small, the degree of depolarization of the target surface increases remarkably as the incident angle increases;as the surface roughness increases, the trend gradually slows down.