Exciton-polariton formation at room temperature in a planar ZnO resonator structure

We show the dispersion of exciton-polaritons in an all oxide planar resonator structure. A quasi-bulk ZnO film acts as active medium and as cavity. The mirrors are made of Bragg reflectors consisting of ZrO2 and MgO layers. Despite a limited structural perfection, we have observed a giant energy splitting of the exciton-polariton branches of about 78 meV at maximum using reflectivity and photoluminescence measurements.