短波通滤光片膜系设计

详细介绍用等效折射率概念设计短波通滤光片的原理和计算方法。根据原理和方法，选择二氧化钛（TiO2）作为高折射率材料、二氧化硅（SiO2）作为低折射率材料。首先从理论上计算出用这2种材料设计的波长λ=950～1150nm的短波通滤光片所需要的周期数，然后给出短波通滤光片的主膜系和光谱曲线。由于据此周期数设计出的膜系光谱曲线在750～810nm处的透过率不符合要求，因此对该膜系进行了改进。依照改进的设计进行多次制备，最终制备出了符合要求的短波通滤光片，找到了最佳制备工艺和方法。最后，对制备出来的短波通滤光片薄膜进行了各种环境实验。实验结果表明，膜层的各项指标符合设计要求。

Film system Design for short-wavelength pass filter

The principle and calculation method to design short-wavelength pass filters with a concept of equivalent refractive index is presented in this paper. TiO2was chosen as the material of high refractive index and SiO2 as the material of low refractive index based on the principle and method. Periodicity of short-wavelength pass filter at wavelength λ= 950 ～1150 nm was theoretically designed according to the concept of equivalent refractive index. The main film system and the spectrum curve of the short-wavelength pass filterare presented. The design of the film system was corrected since its transmissivity did not meet the requirement at the range of wavelength λ= 750 ～ 810 nm. The effect of the main processing technology and the film thickness on the optical characteristics of the short-wavelength pass filter is described. As a result of the correction,the best way to make the film system was found. The film system prepared in this way was tested in different environment conditions. The experiment result shows that the specification of this film system can meet the requirement of the design.