2019 journal article
Multi-color holography with a two-stage patterned liquid-crystal element
OPTICAL MATERIALS EXPRESS, 9(3), 1246–1256.
Computer-generated geometric phase holograms (GPHs) can be manufactured with high efficiency and high fidelity using photo-aligned liquidvcrystals. GPHs are diffractive elements, which therefore have a wavelength-dependent output and can generally not be used for the production of color imagery. We implement a two-stage approach that first uses the wavelength-dependent diffraction to separate colors, and second, directs these colors through separate holographic patterns. Moreover, by utilizing the geometric phase, we obtain diffraction efficiencies close to 100% for all wavelengths. We successfully create a white light hologram from RGB input in the lab. We demonstrate that this schematic allows for full control over individual (RGB) channels and can be used for wide-gamut holography by selecting any combination of wavelengths. In addition, we show with simulations how this two-stage element could be used for of true-color holograms.