Shenzhen Key Laboratory of Laser Engineering;
College of Electronic Science and Technology;
Shenzhen University;
Shenzhen 518060;
Department of Applied Physics;
Hong Kong Polytechnic University;
Hong Kong;
China;
State Key Laboratory of Optical Fiber and Cable Manufacture Technology;
Yangtze Optical Fiber and Cable Company Ltd.R&D Center;
Wuhan 430073;