Topological photonics in three and higher dimensions

Topological photonics is a rapidly developing field that leverages geometric and topological concepts to engineer and control the characteristics of light. Currently, the research on topological photonics has expanded from traditional one-dimensional (1D) and two-dimensional (2D) to three-dimensional (3D) and higher-dimensional spaces. However, most reviews on topological photonics focus on 1D and 2D systems, and a review that provides a detailed classification and introduction of 3D and higher-dimensional systems is still missing. Here, we review the photonic topological states in 3D and higher-dimensional systems on different platforms. Moreover, we discuss internal connections between different photonic topological phases and look forward to the future development direction and potential applications of 3D and higher-dimensional systems.