151. Tunable frequency selective surfaces and negative-zero-positive index metamaterials based on liquid crystals
- Author
-
Bossard, Jeremy A., Liang, Xiaotao, Li, Ling, Yun, Seokho, Werner, Douglas H., Weiner, Brian, Mayer, Theresa S., Cristman, Paul F., Diaz, Andres, and Khoo, I.C.
- Subjects
Refractive index -- Measurement ,Algorithms -- Methods ,Liquid crystals -- Properties ,Algorithm ,Business ,Computers ,Electronics ,Electronics and electrical industries - Abstract
We utilize the properties of aligned nematic liquid crystal (LC) cells in the design of: (i) a new type of metamaterial whose index of refraction is tunable from negative, through zero, to positive values and (ii) micron-scale metallodielectric and all-dielectric tunable frequency selective surfaces (FSSs). The metamaterial is constructed by randomly doping a liquid crystal substrate with coated dielectric (non-magnetic) spheres and can be utilized over a large spectral range. FSSs with a liquid crystal superstrate are synthesized using conventional and genetic algorithm methods to exhibit broadband tunable filter characteristics at mid-infrared (mid-IR) wavelengths. These LC tunable FSS structures can be used to develop a new class of infrared/optical switches for terahertz applications. Index Terms--Frequency selective surfaces (FSSs), genetic algorithms (GAs), liquid crystals (LCs), metamaterials, negative index materials (NIMs), terahertz, zero index materials (ZIMs).
- Published
- 2008