1. Department of General Studies, Physics Division, Jubail Industrial College, Jubail Industrial City 31961, Kingdom of Saudi Arabia
2. Institute of Physics, Academia Sinica, Taipei 115, Taiwan
3. Institute of Mechatronic Engineering, National Taipei University of Technology, Taipei 106, Taiwan
4. Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan
5. Department of Physics, National Sun Yat-sen University, Kaohsiung 804, Taiwan