Structural colors generated by the plasmonic resonance of metallic nanostructures, particularly aluminum, have been intensively studied in recent years. However, the inherent Ohmic loss and interband transitions in metals hinder the high efficiency and narrow bandwidth required for pure colors. Here, arrays of asymmetric titanium oxide elliptical nanopixels on a silica substrate are utilized to realize polarization‐sensitive structural colors with high saturation, high efficiency (more than 90%), and high resolution. Owing to Fano resonance resulting from the interference between the radiating waves of dipole resonances and directly reflected waves, perfect narrow reflected spectra can be formed with nearly ideal efficiency in the visible spectrum based on this all‐dielectric nanostructure. In particular, hue‐ and saturation‐tuned colors can be simultaneously obtained under two orthogonally polarized incident lights with apparent color contrast. Based on the superior properties of the titanium oxide metasurface, the proposed design strategy is anticipated to form a new paradigm for practical applications, such as high‐density optical data storage, nanoscale optical elements, sensing, security, and so on.

中文翻译：

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基于全介电纳米像素的具有色相和饱和度调整的偏振敏感结构色

近年来，已经对由金属纳米结构，特别是铝的等离子体共振产生的结构颜色进行了深入研究。但是，金属固有的欧姆损耗和带间跃迁阻碍了纯色所需的高效率和窄带宽。在这里，利用二氧化硅基板上的不对称氧化钛椭圆形纳米像素阵列来实现具有高饱和度，高效率（超过90％）和高分辨率的偏振敏感结构色。由于偶极共振辐射波和直接反射波之间的干扰导致了Fano共振，基于这种全介电纳米结构，可以在可见光谱中以几乎理想的效率形成完美的窄反射光谱。尤其是，在两个具有明显色彩对比度的正交偏振入射光下，可以同时获得色调和饱和度调整的颜色。基于二氧化钛超颖表面的优异性能，预期所提出的设计策略将为实际应用形成新的范例，例如高密度光学数据存储，纳米级光学元件，传感，安全性等。