1 Department of Physics, Foshan University, Foshan 528000, CHN
2 Laboratory of Photonic Information Technology, School of Information and Photoelectric Science and Engineering, South China Normal University, Guangzhou 510006, CHN
Key Laboratory of Fiber Optic Sensing Technology and Information Processing for Ministry of Education, Wuhan University of Technology, Wuhan 430070, CHN
1 Key Laboratory of Optical Communication and Lightwave Technologies, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, CHN
2 Department of Electronic Information Engineering, Beijing Institute of Machinery, Beijing 100085, CHN