1. College of Electrical, Engineering and Automation
2. Shandong University of Science and Technology
3. Qingdao 266590
4. China
5. College of Electronic, Communication and Physics
6. Key Laboratory of Transparent and Opto-functional Inorganic Materials
7. Shanghai Institute of Ceramics
8. Chinese Academy of Science
9. Shanghai 200050
10. Institute of Physics
11. Polish Academy of Science
12. 02-668 Warsaw
13. Poland