设计并制备了一种在45°斜入射条件下使用的金属Ag消偏振反射镜,这种反射镜可以实现对目标波长810 nm和850 nm光线的反射,并保持线偏光的偏振方向和偏振消光比。为了消除s和p两偏振分量的分离,在金属Ag膜层上方添加了介质多层膜结构,并利用软件对膜系的结构进行了优化,设计结果的能量和相位特性满足目标需求。介质多层膜选用TiO2和SiO2分别作为高、低折射率材料,薄膜的制备采用了离子束辅助沉积工艺,并利用石英晶体振荡监控膜层厚度。得到了消光比达到10 000∶1以上的样品,实现了光学薄膜器件对能量和相位的控制,满足了偏振编码空间光通信试验的需求。

For reflecting target lights of 810 nm and 850 nm wavelengths, while keeping the polarization directions and pursuing the maximal extinction ratio, a depolarization Ag mirror at incidence angle of 45° is designed and fabricated. Additional multilayers have been deposited above the Ag layer to control the separation of s- and p-polarization components. The film configuration is optimized by software Filmwizard, and the phase and energy parameters meet the design target. TiO2 and SiO2 have been chosen as high- and low-refractive index layer materials respectively. Ion beam-assisted deposition is used to improve packing density of the layers, and quartz crystal oscillator is used to control the thickness of films. The extinction ratio of obtained sample reaches 10 000∶1. Phase and energy control of optical thin films was realized to meet the demands of polarization coding optical communication experiment.