A bilayer dichroic-doped liquid crystal (BDLC) film is fabricated via the uniaxial alignment method and a photopolymerization process. It is found to be useful in dichroic color filters, dual-mode circular polarizers, and chirality detectors. Two kinds of dichroic films with different absorbing wavelengths are cross-stacked to show various colors and contrasts depending on the polarization direction of the incident linearly polarized light, which is comparable with the conventional single-layer dichroic dye-doped (SDLC) film that only shows the contrast difference. This platform can be used in many other applications beyond the applications presented in this study, such as multicolor holograms, optical signal encryption, and electrically tunable devices.
Keywords: chirality; dichroic film; liquid crystals; polarization; reactive mesogen.