Flat Magic Window

TL;DR

This paper introduces a novel flat optical device called a magic window that manipulates light using spin-to-orbital angular momentum coupling, enabling polarization-controlled image display with reconfigurable and structured liquid crystal technology.

Contribution

It demonstrates the first realization of a flat, polarization-switchable magic window using structured nematic liquid crystals and optical spin-to-orbital angular momentum coupling.

Findings

Successfully fabricated a flat magic window device.

Achieved polarization-dependent image switching.

Validated the concept with experimental demonstrations.

Abstract

Magic windows (or mirrors) consist of optical devices with a surface deformation or thickness distribution devised in such a way to form a desired image. The associated image intensity distribution has been shown to be related to the Laplacian of the height of the surface relief. We experimentally realize such devices with flat optics employing optical spin-to-orbital angular momentum coupling, which represent a new paradigm for light manipulation. The desired pattern and experimental specifications for designing the flat optics was implemented with a re-configurable spatial light modulator which acted as the magic mirror. The flat plate, optical spin-to-orbital angular momentum coupler, is then fabricated by spatially structuring nematic liquid crystals. The plate is used to demonstrate the concept of a polarization-switchable magic window, where, depending on the input circular polarization handedness, one can display either the desired image or the image resulting from the negative of the window's phase.