Yang Jhen-Hong, Babicheva Viktoriia E, Yu Min-Wen, Lu Tien-Chang, Lin Tzy-Rong, Chen Kuo-Ping
Institute of Photonic System, College of Photonics, National Chiao-Tung University, Tainan 71150, Taiwan.
Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87131, United States.
ACS Nano. 2020 May 26;14(5):5678-5685. doi: 10.1021/acsnano.0c00185. Epub 2020 Apr 22.
Artificial color pixels based on dielectric Mie resonators are appealing for scientific research as well as practical design. Vivid colors are imperative for displays and imaging. Dielectric metasurface-based artificial pixels are promising candidates for developing flat, flexible, and/or wearable displays. Considering the application feasibility of artificial color pixels, wide color gamuts are crucial for contemporary display technology. To achieve a wide color gamut, ensuring the purity and efficiency of nanostructure resonance peaks in the visible spectrum is necessary for structural color design. Low-loss dielectric materials are suitable for achieving vivid colors with structural color pixels. However, high-order Mie resonances prevent color pixels based on dielectric metasurfaces from efficiently generating highly saturated colors. In particular, fundamental Mie resonances (electric/magnetic dipole) for red can result in not only a strong resonance peak at 650 nm but also high-order Mie resonances at shorter wavelengths, which reduces the saturation of the target color. To address these problems, we fabricated silicon nitride metasurfaces on quartz substrates and applied Rayleigh anomalies at relatively short wavelengths to successfully suppress high-order Mie resonances, thus creating vivid color pixels. We performed numerical design, semianalytic considerations, and experimental proof-of-concept examinations to demonstrate the performance of the silicon nitride metasurfaces. Apart from traditional metasurface designs that involve transmission and reflection modes, we determined that lateral light incidence on silicon nitride metasurfaces can provide vivid colors through long-range dipole interactions; this can thus extend the applications of such surfaces to eyewear displays and guided-wave illumination techniques.
基于介质米氏谐振器的人工彩色像素在科学研究和实际设计中都颇具吸引力。鲜艳的色彩对于显示器和成像至关重要。基于介质超表面的人工像素是开发平面、柔性和/或可穿戴显示器的有前途的候选者。考虑到人工彩色像素的应用可行性，宽色域对于当代显示技术至关重要。为了实现宽色域，在结构色设计中确保可见光谱中纳米结构共振峰的纯度和效率是必要的。低损耗介质材料适合用于通过结构色像素实现鲜艳的色彩。然而，高阶米氏共振阻碍了基于介质超表面的彩色像素有效生成高饱和度的颜色。特别是，红色的基模米氏共振（电/磁偶极子）不仅会在650nm处产生强烈的共振峰，还会在较短波长处产生高阶米氏共振，这会降低目标颜色的饱和度。为了解决这些问题，我们在石英衬底上制作了氮化硅超表面，并在相对较短的波长处应用瑞利异常来成功抑制高阶米氏共振，从而创造出鲜艳的彩色像素。我们进行了数值设计、半解析考量和实验概念验证检查，以证明氮化硅超表面的性能。除了涉及透射和反射模式的传统超表面设计外，我们还确定，氮化硅超表面上的侧向光入射可以通过长程偶极相互作用提供鲜艳的颜色；因此，这可以将此类表面的应用扩展到眼镜显示器和导波照明技术。
