1. Songshan Lake Materials Laboratory, Dongguan 523808, P. R. China
2. Institute of Physics, Chinese Academy of Science, Beijing, 100190, P. R. China
3. MOE Key Laboratory of Laser Life Science &Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
4. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China