Invisibility cloak inside a Luneburg lens: Experimental demonstration of birefrigent transformation optics devices

TL;DR

This paper reports the first experimental realization of birefrigent transformation optics devices that can manipulate different polarizations of light independently, using lithographically defined waveguides to achieve polarization-dependent cloaking and lensing effects.

Contribution

It introduces a novel birefrigent transformation optics device based on lithographic waveguides, demonstrating polarization-dependent control of light in a practical setup.

Findings

Successful experimental demonstration of birefrigent TO devices

Wavelength and polarization-dependent performance characterized

Extended control of light on submicrometer scales achieved

Abstract

Transformation optics (TO) has recently become a useful methodology in the design of unusual optical devices, such as novel metamaterial lenses and invisibility cloaks. Very recently Danner et al. [1] have suggested theoretical extension of this approach to birefrigent TO devices, which perform useful and different functions for mutually orthogonal polarization states of light. Theoretical designs which operate as invisibility cloak for one polarization while behaving as a Luneburg lens for another orthogonal polarization have been suggested. Here we report the first experimental realization of similar birefrigent TO designs based on lithographically defined metal/dielectric waveguides. Adiabatic variations of the waveguide shape enable control of the effective refractive indices experienced by the TE and TM modes propagating inside the waveguides. We have studied wavelength and polarization dependent performance of the resulting birefrigent TO devices. These novel optical devices considerably extend our ability to control light on submicrometer scales.