1. Department of Electrical Engineering, National Chung Hsing University, Taichung, Taiwan
2. Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
3. Graduates Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung City, Taiwan
4. Department of Electronic Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung, Taiwan