High-efficiency aerial display using a liquid crystal polarization grating, a retroreflector array, and a right-angle prism

An aerial display scheme consisting of an orthogonal circular polarization grating (OCPG), a waveplate, a retroreflector array (RRA), and a right-angle prism (RAP) was developed. Because of the OCPG’s functionality, retroreflected light from the RRA is transmitted through the RAP boundary surface by avoiding the total reflection condition. The proposed system can potentially increase optical throughput to 100% by designing the boundary surface incidence angle to be Brewster’s angle. The scheme’s feasibility was demonstrated experimentally using an OCPG and waveplate that were fabricated from polymer liquid crystal with optical anisotropy using a photoalignment technique. The scheme should be used as a type of aerial display that is compatible with polarization-diffractive elements called Pancharatnam–Berry phase elements.