A polarizer-free three step switch using distinct dye-doped liquid crystal gels

A polarizer-free three step switch using distinct dye-doped liquid crystal (LC) gels is demonstrated in reflective mode. By controlling the spatial distribution of the density of polymer networks, the distinct dye-doped LC gels can produce multiple states: bright, dark, and information states without patterning indium-tin oxide. The multiple states are generated by adapting different polymer network density in different display regions. The dark state is due to the combination of scattering and absorption. It can be further extended for a four step switch. The potential applications are decorative displays, electrically tunable iris, and electrically tunable low pass or high pass filter.