1Centre for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
2State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
3Institute for Energy Efficiency, University of California Santa Barbara, Santa Barbara, California 93106, USA
4Electrical and Computer Engineering Department, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
5Wuhan National Laboratory for Optoelectronics & School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
6National Information Optoelectronics Innovation Center, China Information and Communication Technologies Group Corporation (CICT), Wuhan 430074, China
7State Key Laboratory of Optical Communication Technologies and Networks, China Information and Communication Technologies Group Corporation (CICT), Wuhan 430074, China
8Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China