Electrically controlled nanostructured metasurface loaded with liquid crystal : toward multifunctional photonic switch

Abstract

Achieving an efficient spectral tuning in liquid-crystal (LC)-loaded active photonic metamaterials has so far remained a challenge due to strong surface anchoring of LC molecules. This paper reports on a novel approach in the development of hybrid metamaterials that enables to overcome this problem and engage for the first time in-plane switching of liquid-crystal molecules on the nanoscale. Combined with the usual volume switching, it unlocks the full potential of the liquid crystals as a functional component of active metamaterial hybrids operating at optical frequencies. As a result, the resonant response of an active metasurface can now be controlled both in terms of its magnitude and wavelength with the spectral tunability approaching the theoretical limit of 9%. This mechanism of two-way active switching of the hybrid metamaterial is also confirmed theoretically by simulating the distribution of the LC director around the metamaterial fabric.