Polarization-independent terahertz wave modulator based on graphene-silicon hybrid structure  

作　　者：杜亮亮 李泉 李绍限 胡放荣 熊显名 栗岩锋 张文涛 韩家广 

机构地区：[1]College of Electrical Engineering and Automation, Guilin University of Electronic Technology, Guilin 541000, China [2]Center for Terahertz Wave, Key Laboratory of Opto-electronic Information Technology, Ministry of Education, College of Precision Instrument and Optoelectronics Engineering, Tianfin University, Tianjin 300072, China

出　　处：《Chinese Physics B》2016年第2期410-415,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China （Grant No. 61565004）, the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China （Grant Nos, 2013GXNSFDAO19002 and 2014GXNSFGA118003）, the Guangxi Scientific Research and Technology Development Program, China （Grant No. 1598017-1）, the Guilin Scientific Research and Technology Development Program, China （Grant Nos. 20140127-1 and 20150133-3）, and the Special Funds for Distinguished Experts of Guangxi Zhuang Autonomous Region, China.

摘　　要：In this study, we propose and demonstrate a broadband polarization-independent terahertz modulator based on graphene/silicon hybrid structure through a combination of continuous wave optical illumination and electrical gating.Under a pump power of 400 mW and the voltages ranging from-1.8 V to 1.4 V, modulation depths in a range of-23%–62% are achieved in a frequency range from 0.25 THz to 0.65 THz. The modulator is also found to have a transition from unidirectional modulation to bidirectional modulation with the increase of pump power. Combining the Raman spectra and Schottky current–voltage characteristics of the device, it is found that the large amplitude modulation is ascribed to the electric-field controlled carrier concentration in silicon with assistance of the graphene electrode and Schottky junction.In this study, we propose and demonstrate a broadband polarization-independent terahertz modulator based on graphene/silicon hybrid structure through a combination of continuous wave optical illumination and electrical gating.Under a pump power of 400 mW and the voltages ranging from-1.8 V to 1.4 V, modulation depths in a range of-23%–62% are achieved in a frequency range from 0.25 THz to 0.65 THz. The modulator is also found to have a transition from unidirectional modulation to bidirectional modulation with the increase of pump power. Combining the Raman spectra and Schottky current–voltage characteristics of the device, it is found that the large amplitude modulation is ascribed to the electric-field controlled carrier concentration in silicon with assistance of the graphene electrode and Schottky junction.

关 键 词：TERAHERTZ MODULATOR GRAPHENE 

分 类 号：TN761[电子电信—电路与系统]