1. Department
of Opto-electronics
and Information Engineering, School of Precision Instruments and Opto-electronics
Engineering, Tianjin University, Tianjin
300072, People’s Republic of China
2. Key Laboratory of Optoelectronic
Information Technology (Tianjin University), Ministry of Education, Tianjin, 300072, People’s Republic
of China
3. Department of Electronic
Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon,
Hong Kong, People’s Republic of China