Advances in strong light-matter coupling in bulk/multilayer transition metal dichalcogenides

Transition-metal dichalcogenides (TMDCs), as prototypical two-dimensional van der Waals materials, have attracted widespread attention because of their distinctive electronic band structures and excellent optical properties. Compared with monolayers, bulk and multilayer TMDCs combine a high refractive index with robust excitonic responses, thereby enabling pronounced light-matter interactions over the visible-to-near-infrared range. In recent years, studies of strong coupling in TMDCs have progressed rapidly, achieving strong coupling between excitons and optical modes such as Mie resonances, Fabry–Pérot (FP) cavities, and quasi-bound states in the continuum. This article focuses on strong coupling in bulk/multilayer TMDCs, provides a systematic overview of the latest advances, summarizes research across different optical cavity platforms—including plasmonic cavities, FP cavities, and high-index dielectric resonators/nanoantennas—and offers an outlook on future developments.