Reduction of converging distance change in an aquatic display formed with aerial imaging by retro-reflection in conjugated optical structure

This paper proposes an optical system for aquatic display that shows an image in water. The aquatic image is formed by utilizing aerial imaging by retro-reflection, which converges light by a retro-reflector and a beam splitter. Refraction on intersection between air and another material causes spherical aberration, which changes light-converging distance. In order to reduce the converging distance change, the light-source component is filled with water so that the optical system becomes conjugate including the medium. We analyzed converging of light in water by simulations. Furthermore, we have confirmed effectiveness of conjugated optical structure experimentally by use of a prototype.