Strong exciton-photon coupling in a monolithic ZnO/(Zn,Mg)O multiple quantum well microcavity

We report on strong exciton-photon coupling in an epitaxially grown (Zn,Mg)O-based lambda-microcavity (MC) containing four 3.5 nm wide ZnO quantum wells (QWs) as active layers. At 5 K, the observed Rabi splitting in absorption is 26 meV, while the inhomogeneous linewidth of A and B excitons in similar QWs without a MC is about 10 meV. The strong coupling regime (SCR) is lost between 150 K and 200 K due to additional homogeneous broadening. From transfer matrix calculations, we deduce that increasing the number of QWs per cavity length can extend the SCR up to room temperature. (C) 2011 American Institute of Physics. [doi:10.1063/1.3657527]