Nanostructured plasmonic metapixels

14 Jul 2017

State-of-the-art pixels for high-resolution microdisplays utilize refective surfaces on top of electrical backplanes. Each pixel is a single fxed color and will usually only modulate the amplitude of light. With the rise of nanophotonics, a pixel’s relatively large surface area (~10μm$^2$), is in efect underutilized. Considering the unique optical phenomena associated with plasmonic nanostructures, the scope for use in refective pixel technology for increased functionality is vast. Yet in general, low refectance due to plasmonic losses, and sub-optimal design schemes, have limited the real-world application. Here we demonstrate the $\textit{plasmonic metapixel}$; which permits high refection capability whilst providing vivid, polarization switchable, wide color gamut fltering. Ultra-thin nanostructured metal-insulatormetal geometries result in the excitation of hybridized absorption modes across the visible spectrum. These modes include surface plasmons and quasi-guided modes, and by tailoring the absorption modes to exist either side of target wavelengths, we achieve pixels with polarization dependent multicolor refection on mirror-like surfaces. Because the target wavelength is not part of a plasmonic process, subtractive color fltering and mirror-like refection occurs. We demonstrate wide color-range pixels, RGB pixel designs, and in-plane Gaussian profle pixels that have the potential to enable new functionality beyond that of a conventional ‘square’ pixel.