Tunable Metasurfaces with Liquid Crystals

Abstract

Intensive researches in the area of metasurfaces have provided a new insight to obtain flat and compact optical systems. In this letter, we numerically show that, highly efficient tunable beam steering effect in transmission mode is achieved at wavelength lambda = 550 nm using nematic liquid crystals (LCs) infiltrated into double sided metasurfaces. Using the electro-optical feature of LCs, the phase profile of the metasurfaces is controlled and thus, the transmitted beam is deflected within the range from -15 degrees to 15 degrees steering angles. Transparent dielectric materials are used in the designed structure that provides highly efficient beam-steering; the corresponding transmission efficiency is above 83% in the visible spectrum, which is another superiority of the proposed hybrid tunable structure over present plasmonic/metamaterial approaches. The designed metasurface still preserves its beam deflection property covering the visible spectrum and hence, such hybrid structure can be implemented for broadband electro-optically controllable beam steering applications.