1. Department of Electrophysics, National Chiao Tung University, Hsin-chu 300, Taiwan
2. Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
3. Advanced Optoelectronics Technology Center, National Cheng Kung University, Taiwan
4. Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsin-chu 300, Taiwan
5. Department of Photonics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
6. Department of Electronics Engineering, National Chiao Tung University, Hsin-Chu 300, Taiwan
7. Advanced Display Technology Research Center, AU Optronics, No.1, Li-Hsin Rd. 2, Hsinchu Science Park, Hsin-Chu 30078, Taiwan