摘要
提出一种偏振不敏感且高选择性的新型纳米结构颜色滤波器.当平面光入射到超材料表面时,金属与介质交界处会发生表面等离子体共振和光学异常透射现象,部分频率的光被束缚在微纳结构中,而其他频率的光发生透射,从而实现滤色效果.采用时域有限差分法,对4种不同结构的滤波器的透射光谱和颜色显示规律进行研究.同时,还研究了结构周期、圆环直径、十字架宽度和偏振角等参数对透射光谱和滤波特性的影响.结果表明:与单层表面等离子结构相比,所提双层等离子体亚表面结构模型的透射率更高;在可见光波段内,该滤波器具有偏振不敏感特性,半峰全宽的最小值为23.26 nm,并且具有90.5％的高透射率.这项研究为下一代颜色滤波器的设计提供了理论参考.
Abstract
Objective Color filters are often made of thin films or dye coatings,but are limited by optical diffraction restrictions,they have low resolution and are sensitive to high temperatures and prolonged ultraviolet(UV)ray exposure.Meanwhile,microstructure-based color filters are more adaptable under application scenarios since they may get the necessary light wavelengths by modifying structural or material factors.Microstructure-based color filters have the advantages of stable performance,tunability,and manufacturability over conventional color filters.Additionally,they are usually made of inorganic or high-temperature durable materials,which have a longer service life with extensive applications in many fields,such as complementary metal oxide semiconductor(CMOS)image sensors,liquid crystal screens,and pixel development.Methods A top double-layer cross circle and a bottom buffer layer comprise the color filter presented in our study.The metal Al and the hydrogen silsesquioxane(HSQ)polymers make up the double-layer cross circle.The bottom is made up of three dielectric layers:a buffer layer of TiO2,a waveguide layer of A12O3,and a substrate layer of SiO2.The finite difference time domain(FDTD)method is adopted to conduct a comparative investigation into the transmission spectra and color display patterns of four different structural filters.The effects of the structural period,cross ring diameter,cross width,and polarization angle on the transmission spectra and filtering characteristics are also examined.Results and Discussions Compared to single-layer construction,the designed color filter using a double-layer cross circle structure has a greater transmittance and reduced full width at half maximum(FWHM).The filter can achieve high transmittance of up to 90.5％at vertical incidence[Fig.5(b)]and the minimum FWHM at the structural period is L1=W1=360 nm[Fig.1(a)].Meanwhile,the resonance wavelength of the transmission peak remains essentially constant over the polarization range of 0-90°(Fig.5),and the transmittance remains above 50 when the angle of incidence is varied from 0 to 30°(Fig.6).Conclusions We propose a polarization-insensitive and highly selective color filter.FDTD numerical simulation is adopted to investigate and compare the cross ring double-layer subsurface structure to the single-layer plasmonic structure.The results show that combining the double-layer subsurface structure with the dielectric can result in a higher transmittance and narrower FWHM,thus leading to a more effective color selection in the visible wavelength range and robust interference resistance.When the angle of the polarized light is changed from 0 to 90°,the resonance peak position of the simulated transmission spectrum varies somewhat,and the accompanying chromaticity coordinate point moves within a small range.This means that the output properties of the filter are consistent across polarization angles,allowing the filter to be employed in structural applications.
基金项目
国家自然科学基金(62165004)
国家自然科学基金(61805053)
广西自然科学基金(2023GXNSFAA026108)
桂林电子科技大学研究生创新项目(2022YCXS047)
桂林电子科技大学研究生创新项目(2021YCXS040)
广西精密导航技术与应用重点实验室主任基金(DH202313)
NETL
NSTL
万方数据