Polarization‐Controlled Transmissive Plasmonic Color Filter Using a Dimer‐Aperture Array

Complex color and polarization selective technologies are of increasing importance in scientific, security, and commercial imaging applications. A new dimeric plasmonic filter structure based on periodic aperture arrays is reported to provide an effective method for making planar color‐selective structures by exploiting the properties of extraordinary optical transmission in thin metal films. The visible band transmission‐mode polarization‐dependent color filters reported in this work exploit only a single layer of aluminum patterned using a hexagonally periodic dimer‐ellipse aperture structure. It is shown experimentally that the structure exhibits a minimum extinction ratio of over 20, 100, and 150 for red, green, and blue channels respectively, and a peak transmission of over 30%. It is demonstrated that dual images can be encoded using polarization selectivity into a single structure. The fidelity of the method is demonstrated with micro‐scale reproductions of complex artworks showing the ability to reproduce 76% of the sRGB color gamut with polarization selectivity. The structure can be readily fabricated with only a single‐step lithography and etching process, so that the technique may be widely used.