Topological Photonic States in Waveguide Arrays

Topological photonics, accompanied by the ability to manipulate light, has emerged as a rapidly growing field of research. More platforms for displaying novel topological photonic states are being explored, thus offering efficient strategies for the realization of robust photonic devices. Optical waveguide arrays, described as a (n+1)-dimensional system, are ideal platforms for studying topological photonics because of the characteristic that can exhibit light dynamics. Here, this work reviews the experimental implementations of the various topological phases in the optical waveguide arrays, and specifically discusses novel physical phenomena arising from the combination of topology with non-Hermitianity and nonlinearity. It is believed that topological waveguide arrays provide powerful support for enriching topological physics and promoting the development of topological photonic integrated devices. This work reviews the major experimental progress in topological waveguide arrays, focusing on photonic topological phases and their interactions with non-Hermitianity and nonlinearity. Topological waveguide arrays enable topological physics to be combined with practical applications, greatly promoting the development of topological photonic integrated devices. image