1. Key Laboratory of In-Fiber Integrated Optics, Ministry Education of China, and College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China
2. State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, Changchun 130022, China
3. School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen 518172, China
4. Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China