1. Department of Photonics, National Cheng Kung University, Tainan, Taiwan
2. Department of Electrical Engineering, Feng Chia University, Taichung, Taiwan
3. Opto-Electronics Technology Section Energy and Agile System Department, Metal Industries Research and Development Centre, Kaohsiung, Taiwan
4. Micro Nano System Center, School of Information Science and Technology, Fudan University, Shanghai, China