1. Institute for Laser Science; University of Electro-Communications; 182-8585 Tokyo Japan
2. Laboratory of Advanced Laser Materials and Devices; Jiangsu Normal University; 221116 Xuzhou P.R. China
3. Institute of Crystal Materials; Shandong University; 250100 Jian P.R. China
4. Institute of Crystallography; Russian Academy of Sciences; 119333 Moscow Russia