Exciton-polariton

In physics, the exciton–polariton is a type of polariton; a hybrid light and matter quasiparticle arising from the strong coupling of the electromagnetic dipolar oscillations of excitons (either in bulk or quantum wells) and photons.^[1] Because light excitations are observed classically as photons, which are massless particles, they do not therefore have mass, like a physical particle. This property makes them a quasiparticle.