渐变折射率薄膜因为消除了界面而克服了传统的分层介质膜的固有弊端。探讨了一种基于这种渐变膜系的设计方法。从小波理论及渐变折射率增透理论出发,以分层介质高反膜系为参照,给出了采用梳状(Rugate)滤光片设计不同类型颜色滤光片的设计原理,并以目前背投系统中使用的红、绿、蓝颜色滤光片为指标,理论设计出了具有优良光谱特性的红、绿、蓝颜色滤光片;对该设计结果进行了角度敏感性分析、偏振效应分析并与传统的反射膜叠加法得到的分层膜系进行比较,发现通过梳状滤光片理论设计的滤光片较传统的多层膜滤光片具有更小的角度敏感性和较小的偏振效应。

The gradient refractive index coating overcomes the initial disadvantages of the traditional discrete coating by eliminating the interfaces. A way of designing this kind of coatings is provided. Based on the wavelets theory and the gradient refractive index antireflection theory, with the high-reflection discrete multilayer dielectric coatings as the reference, the design principle with Rugate filters of different type and color filters is presented, and red, blue and green color filters with high spectral performance are designed theoretically according to the targets of color filters used in the rear display system. The angular sensitivity and polarization effect of the new design are compared with the multilayer coating obtained by the traditional high-reflection coating stacking method, and it is found that the former is less sensitive to the incidence angle and exhibits less polarization effect.