双反射对称分束与平行分束偏光镜的新设计

在激光偏光调制技术中,对称分束镜和超大剪切差的平行分束偏光镜受技术和材料的限制,制作难度很大,为了提高偏光棱镜出射光束的对称性和平行分束性,从复式双反射棱镜结构出发,寻找到两种设计方案,一是改变结构角参量φ和β,该设计不仅能保证分束角的对称,而且可以拓宽分束角,并可以根据需要,选择不同的结构角参量以获得合适的对称分束角。二是把出射面为平面改为两个向外凸的平面,能得到剪切差大的平行出射的o光和e光,且剪切差大小可根据用户要求设计,大大拓宽了双反射偏光棱镜的使用范围。实验结果与理论结果基本一致。

A novel design of bireflective symmetric beam splitting prism and parallel beam splitting prism

In the technology of laser modulation,it is very difficult to produce bireflective symmetric beam splitting prism and parallel beam splitting prism with large shear difference because of technical and material restrictions.In order to improve the symmetry and parallelism of output beams of a polarization prism,two design schemes are presented from the perspective of the structure of bireflective prism.One scheme is to change angle parameters φ and β,which can not only ensure the symmetry of the splitting beam angle,but also broaden the splitting angle.Also,according to requirements,appropriate symmetric splitting angle can be obtained by choosing different angle parameters.Another scheme is to change one flat face of the exit facet into two convex faces,therefore,big shear difference can be obtained and the shear of the prism can be designed according to the customer's requirements.As a result,the application scope of the bireflective prism will be widened greatly.The calculated result is well in agreement with experiments.