1. Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology of Chinese Academy of Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
2. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
3. University of Chinese Academy of Sciences, Beijing 100049, P. R. China
4. Institute of Functional Crystal Materials, Tianjin University of Technology, Tianjin 300384, P. R. China