设计并研制了基于声光晶体的1 300~3 400 nm波段超宽带减反射膜.运用电子束真空沉积系统,采用双材料共蒸发技术,解决了膜系设计时所需材料的折射率匹配和相应波段膜层吸收的问题,吸收在工作波段减少到0.7%.在共蒸发过程中,先沉积蒸发速率不稳定的材料,待蒸发速率稳定后,同时沉积另一种蒸发速率较稳定的材料,可提高共蒸发时两种材料的质量配比准确度从而获得所需要的折射率.制备的薄膜在所需波段平均透射率大于96%,薄膜满足相应的环境检测要求.

The ultra-broad band anti-reflection film in 1 300~3 400 nm has been designed and fabricated on acousto-optic crystal.Using electron beam vacuum deposition system and Utilizing technology of co-evaporation of two materials,some obstacles have been overcome,such as obtaining right refractive index from limited materials,eliminating unwished absorption in corresponding band,Absorption is reduced to 0.7%.Through tests,it was found that during the process of co-evaporation,when the material with less stable evaporation rate was evaporated in the first place,and the more stable material wasn′t set to start evaporation until the former material get a steady evaporation rate,the mass ratio of two materials can get tremendous improvements,which is helpful in obtaining the expected index of refraction as well.This method was tested to be feasible through theoretical simulation.The average transmissivity of film prepared in the corresponding band is over 96% ,the film meetenvironment requirements.