为了提高开放型回归器件在808 nm波长处的反射性能,分析了玻璃微珠折射率对定向回归反射的影响。利用光学仿真软件TracePro对具有3种不同折射率(1.93、2.00和2.20)的回归反射器件结构单元(玻璃微珠)的回归反射性能进行模拟分析,得到了光线垂直入射时采用普通基底的传统开放型回归器件结构单元的理论反射率仅为23.6%,采用高反射基底时,理论最高反射率可达98.1%,回归器件的反光性能提高了3倍。在808 nm波长处制备了反射率为99.3%的高反射光学薄膜,并在镀有此高反射光学薄膜的基底上制备了高反射回归器件。分别对使用两种基底的回归器件进行测试,结果表明,在高反射基底上使用折射率为1.93的玻璃微珠制成的回归器件具有最佳的回归反射率,光线垂直入射时的回归反射率可达46.2%。

Herein, to improve the reflectivity of open-type retro-reflectors at 808-nm wavelength, the impact of glass micro-beads' refractive index on the retro-reflection is theoretically analyzed. The optical simulation software TracePro is used to simulate and analyze the performances of three retro-reflector's structural units (glass micro-beads) with different refractive indexes (1.93, 2.00, and 2.20). The theoretical reflectivity of the conventional open-type retro-reflector's structural unit on the ordinary substrate is only 23.6% when the light is perpendicularly incident, however its theoretical maximum reflectivity is enhanced by 3 times, reaching 98.1%, when a high-reflectivity substrate is used. A high-reflectivity optical film having a reflectivity of 99.3% is designed and fabricated at 808-nm wavelength, and a retro-reflector on the substrate coated with such high-reflectivity optical film is prepared. Retro-reflectors using these two types of substrates are experimentally evaluated, and the results demonstrate that the glass micro-beads with the refractive index of 1.93 on the high-reflectivity substrate provide the best retro-reflectivity. At vertical incidence, the retro-reflectivity value of the retro-reflector on the high-reflectivity substrate reaches 46.2%.