1. State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
2. College of Instrumentation & Electrical Engineering, Jilin University, 938 Ximinzhu Street, Changchun 130021, China
3. College of Engineering, Shantou University, 243 Daxue Road, Shantou 515063, China
4. Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States