Nano-Dispersed Liquid Crystalline Structures for Tunable Negative-, Zero-, and Positive Index Materials in the Optical-Terahertz Regimes

We describe here three approaches to realize tunable or reconfigurable negative-zero-positive index materials: (1) planar nano-structured frequency selective surfaces [FSS] with aligned nematic liquid crystal; (2) core-shell nano-size spheres randomly distributed in a bulk nematic liquid crystal matrix; (3) magneto-optics active cholesteric liquid crystal as 1-D photonic crystal. Such metamaterials can be designed for applications in the optical, terahertz and microwave regimes.