1. Advanced Photonic Technology Laboratory, College of Electronic and Optical Engineering, and the College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing, China
2. School of Physics and Optoelectronic Engineering, Nanjing University of Information Science and Technology, Nanjing, China
3. Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Shanghai University, Shanghai, China