1. Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai 200433, China
2. Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
3. College of Electronic and Optical Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
4. Department of Microelectronics, Delft University of Technology, Delft 2628 CD, Netherlands