Electrically Tunable Critically Coupled Terahertz Metamaterial Absorber Based on Nematic Liquid Crystals

Abstract

Technology to efficiently handle light in the terahertz range is sought for a wide range of applications, including nondestructive testing, medical diagnostics, and weapons detection. Liquid-crystal devices are cheap and promising, but currently suffer from high operating voltage and long response times. The authors exploit coupling between periodically arranged patch resonators and external fields to propose a low-voltage absorber whose reflectance can be modulated from nearly 0 to 90%, with switching times around 50 ms--a dramatic improvement over existing technology that stands to enable new, low-cost, highly tunable terahertz devices.