Transmissive Color Switch Tapping Into a Polarization-Selective Spectral Filter

Electrically controlled transmissive color switches enabling high brightness were demonstrated, by tapping into a polarization-selective nanostructured spectral filter, which is stacked on a liquid crystal-based polarization switch. The spectral filters, based on one-dimensional subwavelength metallic gratings, function as a polarizer and color filter simultaneously. Three independently fabricated spectral filters provided high transmission beyond 80% at 465, 560, and 615 nm, respectively, for blue, green, and red colors. The proposed color switches incorporating the spectral filters were practically observed to exhibit a bright-color state, with a transmission beyond 63%, and an almost opaque dark state, exhibiting an extinction ratio of ~10 dB and a low insertion loss of ~2 dB for a drive voltage range of 2 V.