1. State Key Laboratory of Terahertz and Millimeter Waves and Department of Electrical Engineering, City University of Hong Kong, Hong Kong SAR, China
2. Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems and the School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, China
3. Department of Electrical Engineering, City University of Hong Kong, Hong Kong SAR, China