1. Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
2. Department of Applied Science, Republic of China Naval Academy, Kaohsiung, Taiwan
3. Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
4. Department of Photonics, National Sun Yat-sen University, Kaohsiung, Taiwan
5. Department of Physics and the Center of Crystal Research, National Sun Yat-sen University, Kaohsiung, Taiwan