1. Department of Electronic Engineering, School of Electronic Science and Engineering, Xiamen University, Xiamen 361005, P. R. China
2. Fujian Key Laboratory of Ultrafast Laser Technology and Applications, Xiamen University, Xiamen 361005, P. R. China
3. New Engineering Industry College, Putian University, Putian 351100, P. R. China
4. School of Physics & Technology, Wuhan University, Wuhan 430072, P. R. China
5. Wuhan University Shenzhen Research Institute, Wuhan University, Shenzhen 518000, P. R. China