Tunable metasurfaces with nematic 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 λ = 550 nm using nematic liquid crystals (LCs) infiltrated into double sided metasurfaces. Using the electrooptical feature of LCs, the phase profile of the metasurfaces is controlled and thus, the transmitted beam is deflected within the range from -15˚ to 15˚ 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.