1. Key Laboratory of In-Fiber Integrated Optics, Ministry of Education and College of Science, Harbin Engineering University, Harbin 150001, China
2. College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
3. Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education and School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025, China