Topological character of a nonlinear square lattice waveguide array
Phys. Rev. A 114, 043523 – Published 19 October, 2026
DOI: https://doi.org/10.1103/th8z-lq81
Abstract
Under nonlinear situations, topological characteristics can be not only maintained, but also efficiently improved or actively produced. However, there has been little systematic study on nonlinear control mechanisms in optical waveguide arrays, notably the dynamics of higher-order topological corner states. In this work, we consider a unique photonic platform that combines optical topological phases with nonlinear reactions. We use quenching dynamics analysis to investigate the dynamic behavior of higher-order topological corner states in two-dimensional square lattice waveguide arrays. Observations of corner state development show that topological phases are robust and weak nonlinearity has little effect on topological boundary or evolutionary features. Nonetheless, the system undergoes a shift from topological or trivial phases to a nonlinearity-induced localization phase due to high nonlinearity. In this case, we observe the spatial distribution of a corner state at various points along the waveguide and demonstrate that these modes do not experience transfer and are limited to their initial locations. This study not only reveals the complex interactions between nonlinear effects and topological properties, but it also provides practical insights for dealing with challenges such as high control complexity and material size limitations that may arise during the practical application of topological photonic crystals.
