Strong coupling between excitons and guided modes in WS2-based nanostructures

Abstract

Transition-metal dichalcogenides (TMDCs) exhibit great potential in light–matter interaction due to their semiconducting nature and remarkable excitonic properties. Here a simple guided resonance structure is proposed to numerically investigate and realize dual-band light absorption exploiting the guided mode resonance (GMR) in the system and the robust exciton in the W S 2 monolayer. The dispersive GMR can strongly interact with the nondispersive exciton state by tuning the incident angle, resulting in remarkable Rabi splitting and the emergence of two hybrid polariton bands. The strong GMR–exciton coupling behavior can be well described by the classic oscillator model. The influence of the geometrical parameters on the spectral response is investigated. In addition, we also find that the Rabi splitting is strongly affected by the position of the W S 2 monolayer in the dielectric slab. Our findings provide a simple route for realization of hybrid light–TMDCs interactions, which may inspire related studies on compact, scalable, and easy-to-fabricate TMDC-based devices.