Continuous angle-tunable birefringence with freeform metasurfaces for arbitrary polarization conversion.

ABSTRACT: Birefringence occurs when light with different polarizations sees different refractive indices during propagation. It plays an important role in optics and has enabled essential polarization elements such as wave plates. In bulk crystals, it is typically constrained to linear birefringence. In metamaterials with freeform meta-atoms, however, one can engineer the optical anisotropy such that light sees different indices for arbitrary-linear, circular, or elliptical-orthogonal eigen-polarization states. Using topology-optimized metasurfaces, we demonstrate this arbitrary birefringence. It has the unique feature that it can be continuously tuned from linear to elliptical birefringence, by changing the angle of incidence. In this way, a single metasurface can operate as many wave plates in par

SUBMITTER: Shi Z 

PROVIDER: S-EPMC7269657 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature