1. College of Information Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066000, China
2. The Key Laboratory for Special Fiber and Fiber Sensor of Hebei, Qinhuangdao, Hebei 066000, China
3. Key Lab of Industrial Computer Control Engineering of Hebei Province, Yanshan University, Qinhuangdao, Hebei 066000, China