Graphene/liquid crystal based terahertz phase shifters

TL;DR

This paper presents a graphene/liquid crystal based terahertz phase shifter that achieves continuous tunability and low voltage operation, utilizing graphene's high conductivity and transmittance at terahertz frequencies.

Contribution

It introduces a novel liquid crystal phase shifter with graphene electrodes, demonstrating effective phase control at low voltages and analyzing the effects of graphene layers on performance.

Findings

Maximum phase shift of 10.8 degrees

Saturation voltage of 5 V

Transmittance depends on graphene layer number

Abstract

Due to its high electrical conductivity and excellent transmittance at terahertz frequencies, graphene is a promising candidate as transparent electrodes for terahertz devices. We demonstrate a liquid crystal based terahertz phase shifter with the graphene films as transparent electrodes. The maximum phase shift is 10.8 degree and the saturation voltage is 5 V with a 50 um liquid crystal cell. The transmittance at terahertz frequencies and electrical conductivity depending on the number of graphene layer are also investigated. The proposed phase shifter provides a continuous tunability, fully electrical controllability, and low DC voltage operation.