Liquid crystal clad near-infrared metamaterials with tunable negative-zero-positive refractive indices

D H. Werner, Department of Electrical Engineering, The Pennsylvania State University
Do-Hoon Kwon, Department of Electrical Engineering, The Pennsylvania State University
Iam-Choon Khoo, Department of Electrical Engineering, The Pennsylvania State University
Alexander V. Kildishev, Birck Nanotechnology Center, Purdue University
V. M. Shalaev, Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University

Abstract

Near-infrared metamaterials that possess a reconfigurable index of refraction from negative through zero to positive values are presented. Reconfigurability is achieved by cladding thin layers of liquid crystal both as a superstrate and a substrate on an established negative-index metamaterial, and adjusting the permittivity of the liquid crystal. Numerical results show that the index of refraction for the proposed structure can be changed over the range from -1 to +1.8 by tuning the liquid crystal permittivity from 2 to 6 at a wavelength of 1.4 mu m.