Polarization tuned light-matter coupling in exciton-polariton manifold*

Group VII TMDs like ReS₂ show strongly anisotropic electronic and optical properties from bulk to monolayer limit without any drastic change, making it ideal for multilayer photonic devices. Here, we demonstrate highly tunable strong light-matter coupling in ReS₂, with Rabi splitting of up to 68 meV, utilizing the interaction of anisotropic polarized excitons and the photonic mode supported in the ReS₂ layer placed on a DBR structure. The coupling strength of such highly anisotropic exciton-polaritons can be tuned by rotation of incident beam polarization. It also can be used to switch between two independent three-body coupled oscillators in this system. In addition, layer thickness and temperature variation provide a way to manipulate the coupling strength and polariton detuning. Our result paves the way to engineer devices for application in polarization-controlled photonics.