Short Bio:

Xingang Ren received the Ph.D. degree in the Department of Electrical and Electronic Engineering at the University of Hong Kong (HKU) in 2016. From Nov. 2016 to Nov. 2018, he worked as a Research Associate at HKU. He is currently an Associate Professor in the Information Materials and Intelligent Sensing Laboratory of Anhui Province and School of Electronic and Information Engineering, Anhui University, China. His research interests include theoretical and computational research in electromagnetics and optics, focusing on multiphysics and interdisciplinary research.
Dr. Ren is the Senior Member of the Chinese Institute of Electronics, and member of IEEE and OSA. He was a recipient of the hundred talents of Anhui Province and Young Wanjiang Scholar of Anhui Province. He severs as the guest editor of Frontiers in Materials, Nanomaterials etc., he has also served on the review boards of various technical journals, and many international conferences as a TPC Member, Session Organizer, and the Session Chair.

Title: Dual Quasi-Bound States in the Continuum Modes for Optical Activity Manipulation

Abstract: The Bound states in the continuum (BIC) mode reside inside the continuous spectrum of the extended radiating state, which is a perfectly confined mode in space with a theoretically infinite lifetime. The quasi-bound states in the continuum (quasi-BIC) are a particular resonant state, which can be regulated by the degree of symmetry breaking in nanostructures. Here, we propose a fourfold rotationally symmetric (C4v) metasurface supporting the dual quasi-BIC modes. The Fano characteristics have observed in the near-infrared region. The resonant peaks of the dual quasi-BIC modes can be adjusted flexibly and independently with a simple breaking of the structural symmetry. Importantly, the dual quasi-BIC modes demonstrate the extraordinary capability in controlling the optical activity and reveal the polarization selectivity. The topological charges and multipole analysis have adopted to understand the underlying physics. This work will offer us more freedom for controlling the resonance and optical activity by the quasi-BIC modes, which is promising to engineer the optical device in displaying and optics communications.