Broadband tunable liquid crystal terahertz waveplates driven with porous graphene electrodes  

作　　者：Lei Wang Xiao-Wen Lin Wei Hu Guang-Hao Shao Peng Chen Lan-Ju Liang Biao-Bing Jin Pei-Heng Wu Hao Qian Yi-Nong Lu Xiao Liang Zhi-Gang Zheng Yan-Qing Lu 

机构地区：[1]National Laboratory of Solid State Microstructures,Collaborative Innovation Center of Advanced Microstructures and College of Engineering and Applied Sciences,Nanjing University,Nanjing 210093,China [2]Research Institute of Superconductor Electronics(RISE),School of Electronic Science and Engineering,Nanjing University,Nanjing 210093,China [3]State Key Laboratory of Materials Oriented Chemical Engineering,College of Materials Science and Engineering,Nanjing Tech University,Nanjing 210009,China [4]Department of Chemistry,Tsinghua University,Beijing 100084,China

出　　处：《Light(Science & Applications)》2015年第1期477-482,共6页光（科学与应用)（英文版）

基　　金：This work was sponsored by the 973 programs(Nos.2011CBA00200 and 2012CB921803);the National Natural Science Foundation of China(Nos.61490714,11304151 and 61435008);the PhD Programs Foundation of the Ministry of Education of China(No.20120091120020);Yan-Qing Lu appreciates the support from National Science Fund for Distinguished Young Scholars(No.61225026);the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT13021);Biao-Bing Jin appreciates the support from the 973 program(No.2014CB339800);the National Natural Science Foundation of China(Nos.61371035 and 11227904);Cooperative Innovation Centre of Terahertz Science,University of Electronic Science and Technology(Chengdu,China).

摘　　要：Versatile devices,especially tunable ones,for terahertz imaging,sensing and high-speed communication,are in high demand.Liquid crystal based components are perfect candidates in the optical range;however,they encounter significant challenges in the terahertz band,particularly the lack of highly transparent electrodes and the drawbacks induced by a thick cell.Here,a strategy to overcome all these challenges is proposed:Few-layer porous graphene is employed as an electrode with a transmittance of more than 98%.A subwavelength metal wire grid is utilized as an integrated high-efficiency electrode and polarizer.The homogeneous alignment of a high-birefringence liquid crystal is implemented on both frail electrodes via a non-contact photo-alignment technique.A tunable terahertz waveplate is thus obtained.Its polarization evolution is directly demonstrated.Furthermore,quarter-wave plates that are electrically controllable over the entire testing range are achieved by stacking two cells.The proposed solution may pave a simple and bright road toward the development of various liquid crystal terahertz apparatuses.

关 键 词：liquid crystal porous graphene terahertz waveplate 

分 类 号：TN2[电子电信—物理电子学]