Nguyen-Huu Nghia, Lo Yu-Lung, Chen Yu-Bin, Yang Tsai-Yu
Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, Tainan City, Taiwan.
Appl Opt. 2011 Feb 1;50(4):415-26. doi: 10.1364/AO.50.000415.
This study realizes integrated polarizer and RGB (red, green, and blue) color filters using single- and multiple-layered subwavelength metallic grating structures. A hybrid numerical scheme based on the rigorous coupled-wave analysis method and a genetic algorithm is used to determine the optimal values of the grating period, filling factor, and grating thickness of three different grating structures, namely, a single-layer grating, a double-layer grating, and a double-layer grating with a lateral shift. The optical performance of the various structures is evaluated and compared in terms of the transmission efficiency at the center wavelengths 700.0 nm, 546.1 nm, and 435.8 nm of red, green, and blue light, respectively, and the extinction ratio over the visible wavelength spectrum (380-780 nm). It is shown that the double-layer grating achieves a transmission efficiency of about 50% and an extinction ratio of around 60 dB. Thus, this grating structure provides a convenient and effective means of achieving the polarizing and filtering functions in LCD panels using a single device.
本研究利用单层和多层亚波长金属光栅结构实现了集成偏振器和RGB（红、绿、蓝）滤色器。基于严格耦合波分析方法和遗传算法的混合数值方案用于确定三种不同光栅结构（即单层光栅、双层光栅和具有横向偏移的双层光栅）的光栅周期、填充因子和光栅厚度的最佳值。分别根据红、绿、蓝光在中心波长700.0 nm、546.1 nm和435.8 nm处的传输效率以及可见光谱（380 - 780 nm）上的消光比，对各种结构的光学性能进行评估和比较。结果表明，双层光栅实现了约50%的传输效率和约60 dB的消光比。因此，这种光栅结构提供了一种使用单个器件在液晶显示面板中实现偏振和滤波功能的便捷有效方法。
