Analyzer-Free and Brightness-Tuning Structural Color Enabled by Reflective Malus-Assisted Metasurface

Metasurfaces provide a versatile platform for vivid structural coloration by tailoring the visible spectrum at the subwavelength scale. A variety of research has been dedicated to broadening the color gamut including hue and saturation. However, the color gamut is limited in a 2D CIE map, which cannot exhibit chiaroscuro information of colorful images due to the lack of brightness tuning. In this work, we propose a passive, reflective and analyzer-free metasurface platform performing arbitrary HSB tunability and exhibiting full color generation by simultaneous spectral and polarizing filtration. A single plasmonic metasurface consisting of aluminum nanorods is demonstrated to generate multiple colors, which are determined by the in-plane dimension of the nanorod. Based on Malus’s law, continuous brightness tuning of these individual colors can be achieved by adjusting the nanorod orientation under linearly polarized illumination, without requiring an additional polarization analyzer in the reflected-light path. Finally, we numerically reproduce the artwork “Portrait of a Musician”, which features photorealistic presentation and stereoscopic impression. Such an approach shows great potential to simply control the color in HSB space with high spatial resolution, which is significant in the applications of next-generation compact reflective displays.