Fig. 1
From: Room-temperature valley coherence in a polaritonic system
Device architecture and optical characterization. a Cavity polariton schematic. The green sheet represents monolayer WSe2. The cavity is assembled by two SiO2/Ta2O5 distributed Bragg reflector (DBR) mirrors with a λ/2 cavity spacing. Strong coupling of excitons and photons leads to the formation of polaritons. b Cavity reflectance and WSe2 PL spectrum. For vertical incidence, cavity resonance is measured as 1.644 eV (red). PL centers at 1.664 and 1.636 eV under ambient conditions before (black dashed) and after (black solid) deposition of the top dielectric layer. c Energy-momentum dispersion of cavity polariton. These curves are fitted by a coupled-harmonic-oscillator model with an 11.4 meV Rabi splitting. Dashed lines represent bare resonances and the solid lines stand for two polariton branches. Errorbars are extracted from least square fitting
