Abstract-Graphene/liquid crystal based terahertz phase shifters

 

Yang Wu, Xuezhong Ruan, Chih-Hsin Chen, Young Jun Shin, Youngbin Lee, Jing Niu, Jingbo Liu, Yuanfu Chen, Kun-Lin Yang, Xinhai Zhang, Jong-Hyun Ahn, and Hyunsoo Yang  »View Author Affiliations
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-21-18-21395&origin=search

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 µm 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.