一维三格点光格子中拓扑振荡及拓扑非对称边缘态  

Topological Oscillations and Asymmetric Edge States in One-dimensional Trimer Lattices

作　　者：张金 江涛 辛国国 党煜 吴高锋 ZHANG Jin;JIANG Tao;XIN Guoguo;DANG Yu;WU Gaofeng(School of Physics,Northwest University,Xi′an 710072,China)

机构地区：[1]西北大学物理学院,西安710072

出　　处：《光子学报》2024年第6期240-250,共11页Acta Photonica Sinica

基　　金：国家自然科学基金(No.12074310)。

摘　　要：为了全面认识奇数格点原胞中拓扑保护对于光束稳定传输的重要性,系统研究了一维三格点光格子模型中的光传输特性。利用能带理论和耦合模方程,对模型进行了模拟和仿真,发现两种在经典的两格点模型中不存在的具有拓扑保护的光传输行为,即具有拓扑保护的类拉比振荡光传输和具有拓扑保护的非对称传输,揭示了这两类光传输现象的物理机制,深入解析了光束振荡的本质,并验证了这两类光传输行为的鲁棒性,强调了光学系统在不同条件下的稳定性和可靠性。该研究可为利用奇数格点原胞中拓扑性质操纵光传输的潜在应用提供启示,并为新型拓扑光学器件的设计提供新的思路。In the Su-Schrieffer-Heeger model,the topological properties and optical evolution dynamics of two-site lattice chains have been extensively studied,providing a theoretical basis for investigating the topological properties of even-length unit cell lattice chains.However,research on the topological properties of odd-site unit cell lattice systems with three or more energy bands is relatively limited.This is because symmetry breaking exists in three-site systems,making it challenging to directly apply theoretical methods developed for even-band systems.Therefore,this study aims to explore topologically protected optical transmission behaviors missing in the classical two-site model using a one-dimensional trimer lattice model,establishing a framework for topological photonics theory applicable to odd-band systems.This model will employ theoretical methods such as coupled mode equations and band theory for investigation.By integrating the one-dimensional trimer lattice model with a waveguide array using coupled mode theory,the model will simulate the evolution process of light beams in the waveguide array.This will involve substituting plane waves into coupled mode equations,adjusting coupling coefficients,and observing localized optical phenomena and intensity distribution during beam transmission.Eigenenergies and wave functions of the model will be computed using band theory,facilitating the generation of real-space band diagrams and probability distribution maps of wave functions.Through analysis of these data and images,a deeper understanding of the mechanisms behind topological oscillating light beams and asymmetric edge states observed in the one-dimensional trimer lattice model can be obtained.Furthermore,by computing topological invariants and statistically analyzing the distribution of edge states,phase diagrams of the system can be plotted,comprehensively displaying the distribution of topological edge states across the entire parameter range.Introducing defects midway through the long-distance evolution

关 键 词：拓扑光子学 拓扑光传输 耦合模方程 光格子 拓扑振荡边缘态 拓扑非对称边缘态 

分 类 号：O436.2[机械工程—光学工程] O436.3[理学—光学]