1. Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
2. Shanghai Advanced Research Institute Zhangjiang Lab, Chinese Academy of Sciences, Shanghai 201210, China
3. Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
4. Faculty of Science and Engineering, University of Chester, Thornton Science Park, Chester, U.K. CH2 4NU
5. Guangxi Key Laboratory of Optoelectronic Information Processing, Guilin University of Electronic Technology, Guilin 541004, China
6. School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, Oklahoma 74078, United States