一种新型对称分束偏光棱镜的设计

为了提高偏光棱镜出射光束的对称性,在Wallaston棱镜的基础上,对出射光端面倾斜适当的角度,在结构角一定的情况下,即可以保证分束角相对入射光方向的对称性。以589.3nm钠黄光为例,给出了出射光端面倾角,棱镜结构角和分束角之间的关系式,并分析了分束角随出射光端面倾角的变化趋势,同时提出了两种相关设计方案。测试结果表明,两出射光束的对称性相当好,理论值与实验值几乎完全吻合,表明该棱镜确是一种较理想的对称分束偏光器件。

A new symmetric beam-splitting polarization prism

To improve the symmetry of emergent beams of a polarization prism,based on the Wallaston prism,the emergent face is inclined with an appropriate angle,so that the symmetry which the beam-splitting angle relative to the incident light direction can be ensured in the case of a certain structure angle.Taking the 589.3nm sodium yellow light for example,the relation formula among the obliquity of the emergent face,the structure angle of the prism and the beam-splitting angle are deduced,and the change trend of the beam-splitting angle along with the emergent face is also analyzed.Two correlative designs are presented at the same time.The testing results indicate that the symmetry is excellent and the experiment value is almost identical with the theoretical value which shows this polarization prism is positively an ideal symmetric beam-splitting polarization device.