Embedding monolayers of 2D materials in directly sputtered monolithic cavities for strong light-matter coupling

We present a monolithic planar Fabry–Pérot microcavity integrating a monolayer of WS 2 using fully sputtered SiO 2 /TiO 2 distributed Bragg reflectors (DBRs). Direct deposition of the top DBR is made possible by protecting the transition metal dichalcogenide monolayer with a thin hexagonal boron nitride (hBN) layer, preserving its optical integrity throughout the fabrication process. The resulting structure supports strong exciton–photon coupling, confirmed by a clear Rabi splitting of (36 ± 4) meV observed in angle-resolved photoluminescence (PL) measurements. This fabrication route avoids complex mechanical assembly or high-temperature processing, offering a robust and scalable alternative for realizing solid-state exciton-polariton systems while allowing precise control of the DBR layer thickness. Our approach simplifies access to monolithic TMDC microcavities, potentially enabling broader experimental exploration of polaritonic and nonlinear optics phenomena.