Dr. Fei Xu received his Ph.D. in Optoelectronics in 2008 from the Optoelectronics Research Centre, University of Southampton, UK. He is currently a professor at the College of Engineering and Applied Sciences, Nanjing University, China. Dr. Xu is a senior member of IEEE and Optica, and the Fellow of SPIE, his current research interests include developing novel fiber devices for ultra-small sensor, laser and imaging systems. During his research career, he has received the National Science Fund for Distinguished Young Scholars (2019) and the National Science Fund for Excellent Young Scholars (2012) from the National Natural Science Foundation of China, the Program for New Century Excellent Talents in University from the Ministry of Education of China (2009), the Science and Technology Award of Jiangsu Province, China (the first prize, 2020). To date, he has authored or coauthored 8 book chapters, granted >40 patents (China and US), and >140 peer reviewed articles in academic journals in the previously mentioned areas. His papers have been cited more than 3,600 times in Web of Science, and he was invited to give more than 60 talks in international conferences.