1. Key Laboratory of Superlight Materials and Surface Technology Ministry of Education College of Materials Science and Chemical Engineering Harbin Engineering University Harbin 150001 P. R. China
2. State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 P. R. China
3. Key Laboratory of In‐Fiber Integrated Optics of Ministry of Education College of Physics and Optoelectronic Engineering Harbin Engineering University Harbin 150001 P. R. China
4. Division of Chemistry and Biological Chemistry School of Physical & Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore