1. Department of Physics
2. National Dong Hwa University
3. Hualien 97401
4. Taiwan
5. Department of Opto-Electronic Engineering
6. Institute of Optoelectronic Sciences
7. National Taiwan Ocean University
8. Keelung 202
9. Department of Applied Materials and Optoelectronics Engineering
10. National Chi Nan University
11. Nantou 54561
12. School of Physics and Astronomy
13. University of Manchester
14. Manchester M13 9PL
15. UK