Compact Transreflective Color Filters and Polarizers by Bilayer Metallic Nanowire Gratings on Flexible Substrates

An integrated transmitted polarizer and reflective color filters with structure of bilayer metallic nanowire grating on a flexible polyethylene terephthalate substrate was demonstrated by theory, experiment, and numerical simulation. Two kinds of waveguide resonances, which led to the comprehensive characters, were analyzed. The slits in the bilayer metallic grating permit the transmission of TM light (transverse magnetic field) in surface plasmon waveguide mode and prohibit the propagating of TE light (transverse electric field) with wavelengths larger than cutoff value to obtain polarization effect. The lateral guiding mode resonances on the interfaces of the metallic/substrate or metallic/air excite surface plasmon waves with certain wavelengths, which makes a single peak in the reflection spectrum of TM light and dips in transmission for color filtering effect of TM light. The experimental results and theoretical analyses are in good agreement. This new bilayer structure featured with nonabsorption, integrated functions and simple fabrication has a great potential in power saving and thickness reduction for display devices.