涡旋光束在反射中的正交偏振特性研究  

Cross polarization effects of vortex beam in reflection

作　　者：张进[1] 周新星[1] 罗海陆[1] 文双春[1] 

机构地区：[1]湖南大学信息科学与工程学院,微纳光电器件及应用教育部重点实验室,长沙410082

出　　处：《物理学报》2013年第17期214-220,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11074068);湖南省自然科学基金(批准号:12JJ7005)资助的课题~~

摘　　要：本文从角谱理论出发建立了涡旋光束在空气-玻璃界面反射时的傍轴传输模型,并研究了反射过程中诱导产生的正交偏振效应.当一水平偏振涡旋光束以不同角度入射时,反射光束的正交偏振分量呈现出类似于一阶厄米-高斯模式的双峰强度分布,而水平偏振分量强度分布呈现与入射光束相似的分布,且只在布儒斯特角附近入射时才现出与正交偏振分量垂直的双峰分布.对于任意线偏振入射光,其正交偏振分量的偏振方向不再垂直于入射时的偏振方向,而是与反射光束的中心波矢垂直,此时正交偏振分量出现有趣的旋转特性,其物理原因归结于任意线偏振光入射时所对应的水平与垂直偏振分量的反射系数不同.最后进行了相关实验验证,发现实验结果与理论分析符合得较好.Based on the angular spectrum theory, we establish a propagation model for vortex beam in reflection at an air-glass interface in the paraxial approximation, and investigate the cross polarization effects. When the horizontal polarization vortex beam is incident at different angles, the cross polarization component of the reflected beam shows a double-peak intensity distribution which is similar to the first-order Hermite-Gaussian mode. The distribution of horizontal polarization component is similar to that of the incident beam, and will show a double-peak intensity distribution which is perpendicular to the distribution of cross polarization components at the Brewster incidence. For the incident beam with arbitrary linear polarizations, we find that the polarized direction of cross polarization component is not perpendicular to the incident polarized direction, but exhibits an interesting rotational characteristic. The physical nature of this phenomenon is attributed to the different reflection coefficients of parallel and perpendicular polarizations. Experimental results agree well with our theoretical analysis.

关 键 词：正交偏振 涡旋光束 任意线偏振 

分 类 号：O436[机械工程—光学工程]