1. Key Laboratory of Advanced Transducers and Intelligent Control System, Ministry of Education of China, College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
2. Key Laboratory of Advanced Transducers and Intelligent Control System, Ministry of Education of China, College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China, and also with the Advanced Institute of Photonic Technology, Guangdong University of Technology, Guangzhou 510006, China.