1. State Key Laboratory of Luminescent Materials and Devices, and Guangzhou Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques South China University of Technology Guangzhou P. R. China
2. Guangzhou Engineering Technology Research and Development Center of Special Optical Fiber Materials and Devices School of Materials Science and Engineering South China University of Technology Guangzhou P. R. China
3. Department of Materials Science and Engineering City University of Hong Kong Kowloon Hong Kong P. R. China
4. Department of Institute of Textiles & Clothing Hong Kong Polytechnic University Kowloon Hong Kong P. R. China
5. College of Optical Science and Engineering State Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou P. R. China