研究了一维亚波长光栅结构彩色滤光片在可见光波段的透射光谱特性。该彩色滤光片由柔性透明基底、介质光栅和金属光栅构成。利用严格耦合波分析法(RCWA)模拟了占空比、介质光栅的厚度、金属光栅的厚度和周期等结构参数对彩色滤光片的透射光谱特性的影响，并在此基础上优化结构参数，设计出一种宽带宽、高透射效率且易于加工的彩色滤光片。该彩色滤光片带宽为85~100 nm，色纯度好；具有高达95%的偏振（TM）光透射效率；只需改变光栅的周期，就可获得针对R，G，B三色的透射光谱，降低了加工彩色滤光片的难度。与其他应用于彩色滤光片的光栅结构相比，所设计的彩色滤光片的中心光谱透射效率提高了12%，且减少了三色输出光谱之间的重叠区域，从而提高了彩色滤光片的色度性能，适合作为液晶平板显示中的滤光器件。

Transmission characteristic of a novel sub-wavelength grating color filter at visible region is investigated theoretically. The device consists of three parts: the flexible transparent substrate, the dielectric grating and the metal grating. By using rigorous couple-wave analysis (RCWA), the transmission characteristic is analyzed as a function of the duty cycle, the thickness of the dielectric grating, the thickness of the metal grating and the period. Based on the simulation results, a high-performance color filter is proposed by optimizing the structural parameters. The bandwidth of the filters are about 85 nm. The peak transmission efficiency of the filters are about 95%. The calculated results show that the peak transmission efficiency of the filters are increased more than 12% compared with the previous color filters incorporating a grating. The overlap of the tricolor output spectra decreases effectively, which will increase the color saturation of the color filter. The proposed color filter is suitable for filtering used in liquid crystal devices.