1. College of Physics University‐Industry Joint Center for Ocean Observation and Broadband Communication Qingdao University Qingdao 266071 China
2. National Demonstration Center for Experiment Applied Physics Education (Qingdao University) Qingdao 266071 China
3. Shandong Provincial University Key Laboratory of Optoelectrical Material Physics and Devices Qingdao 266071 China