Mizutani Akio, Kikuta Hisao, Iwata Koichi, Toyota Hiroshi
College of Engineering, Osaka Prefecture University, Sakai, Japan.
J Opt Soc Am A Opt Image Sci Vis. 2002 Jul;19(7):1346-51. doi: 10.1364/josaa.19.001346.
We describe a new structure of guided-mode resonant grating (GMRG) filters with low sideband reflectance. This GMRG filter consists of a high-index thin film on an antireflective structured surface called "moth-eye structure." Since the high-index film undulates along the surface structure, the film acts as a modulated optical waveguide. An incident light wave satisfying a resonant condition is reflected by the GMRG filter, and nonresonant light waves pass through the filter. This GMRG filter is valid for reducing reflection of nonresonant light waves in a wide spectral range. The resonant reflection of this new filter was investigated by numerical calculation based on an electromagnetic grating analysis. In the case of a triangular antireflective surface structure whose thickness is 2x greater than its period, the sideband reflectance for nonresonant light waves was lower than 0.5% for TM-polarized light in a wide range of wavelengths.
我们描述了一种具有低边带反射率的导模共振光栅（GMRG）滤波器的新结构。这种GMRG滤波器由位于一种称为“蛾眼结构”的抗反射结构化表面上的高折射率薄膜组成。由于高折射率薄膜沿着表面结构起伏，该薄膜起到了调制光波导的作用。满足共振条件的入射光波被GMRG滤波器反射，而非共振光波则透过该滤波器。这种GMRG滤波器在很宽的光谱范围内对于减少非共振光波的反射是有效的。基于电磁光栅分析，通过数值计算研究了这种新型滤波器的共振反射。在厚度比其周期大2倍的三角形抗反射表面结构的情况下，对于TM偏振光，在很宽的波长范围内，非共振光波的边带反射率低于0.5%。
