1. Department of Photonics, Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
2. International Ph.D. Program in Photonics (UST), College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
3. Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
4. Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan