1. Department of Electro-Optical Engineering, Kun Shan University, Yong-Kang District, Tainan 71003, Taiwan
2. National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
3. Department of Electrical Engineering and Institute of Microelectronics, Center for Micro/Nano Science and Technology, Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan