复合式剪切差可调谐平行分束偏光镜

Composite Parallel Splitting Prism with Tunable Shear Difference

为了克服现有平行分束偏光镜剪切差较小且不可调谐的缺点,拓宽平行分束偏光镜的应用范围,采用冰洲石晶体和两块间距可调的三角形玻璃棱镜,制作出造价相对低廉、剪切差大范围内可调谐、且具有优越的分束比和透射比的复合式剪切差可调谐平行分束偏光镜。从理论上分析了该复合式棱镜的剪切差可调谐范围、e光和o光的分束比及未镀增透膜的情况下总的透射比随复合式棱镜中玻璃棱镜的结构角及两块玻璃棱镜的间距等结构参数的变化,并给出了仿真计算结果。依据该结果设计了实验样品,剪切差在1.4～50.2mm范围内可调谐,e光和o光的光强分束比优于1.1,且在未镀增透膜的情况下总的透射比大于80%。

In order to overcome the shortcoming of small and untunable shear difference in the existing parallel splitting prisms,and expand the application scope of the parallel splitting prisms,a composite parallel splitting prism is made by one iceland crystal prism and two triangle glass prisms with adjustable distance.The composite prism has the following advantages： low cost,shear difference tunable in a large scale,excellent splitting ratio and total transmission ratio.The changes of tuning scale,the e light and o light splitting ratio and the total transmission ratio without antireflection film coating of the composite prism with the the change of structure parameters including the distance between the two glass prisms and the glass prism angles are analyzed theoretically.Computer simulation results are given too.Based on the results,an experimental sample is designed and fabricated.When the distance between two glass prisms changes from 15 mm to 180 mm,for the transmitted light via Iceland crystal prism with 3 mm shearing distance,the shearing distance can be tuned between 1.4～50.2 mm.And the splitting ratio of e light and o light is less than 1.1,the total transmission ratio is higher than 80%.