From passive to active manipulation of the polarization states of light via metastructures

Abstract

In this talk, we present our recent work on passive or active manipulation of the polarization state of light with both 2D and 3D metastructures. First, we illustrate an approach to tune efficiently the phase difference of light in two orthogonal directions by controlling the time retardation with a microstructured surface. Second, we demonstrate the general mechanism to construct the dispersion-free metastructure, in which the intrinsic dispersion of the metallic structures is perfectly cancelled out by the thickness-dependent dispersion of the dielectric spacing layer. Third, we present a freely tunable polarization rotator for broadband terahertz waves using a metastructure, and also an example on dynamically switching the polarization state of light based on the phase transition of vanadium dioxide. The investigations provide some guidelines to control the polarization state of light at subwavelength scale.