Polarization-resolved edge states in terahertz topological photonic crystal

作     者：Hao Xiong Qiang Wu Yao Lu Ride Wang Qi Zhang Jiwei Qi Jianghong Yao Jingjun Xu 

作者机构：The Key Laboratory of Weak-Light Nonlinear Photonics Ministry of Education TEDA Institute of Applied Physics and School of Physics Nankai University Tianjin 300457 China 

出 版 物：《Optics express》 

年 卷 期：2019年第27卷第16期

页      面：22819-22826页

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

主　　题：Circular polarization Electromagnetic scattering Finite-difference time-domain method Light sources Photonic crystals Wave propagation 

摘      要：The discovery of topological photonic states has revolutionized our understanding of electromagnetic propagation and scattering. With the introduction of topology, some attractive properties such as unidirectional propagation and robustness against defects and impurities will be endowed to photonic edge modes. In this study, two-dimensionally confined topological edge states were achieved at terahertz (THz) frequency based on an all-dielectric photonic crystal structure. Trivial and nontrivial bandgaps of two deforming honeycomb lattices as well as unidirectional topological edge states were observed. Because the topological edge states with opposite helicity propagated in opposite directions at the interface, a polarization-resolved characteristic was demonstrated here, and thus a continuously tunable power splitter was achieved. This study provides some insights for further THz topological studies and possibilities for THz integrated platforms.