$\mathrm{GaN}∕\mathrm{AlGaN}$ and $\mathrm{InGaN}∕\mathrm{GaN}$ quantum wells (QWs) are investigated as the active region for room-temperature strong exciton-photon coupling in high-quality $\mathrm{AlInN}∕\left(\mathrm{Al}\right)\mathrm{GaN}$ microcavities (MCs). Angular resolved photoluminescence (PL) measurements performed on an $\mathrm{AlInN}∕\mathrm{AlGaN}$ MC with $\mathrm{GaN}∕\mathrm{AlGaN}$ QWs reveal cavity polariton dispersion curves. A vacuum-field Rabi splitting of $30\mathrm{meV}$ is observed, from which an exciton oscillator strength of $4.8\times {10}^{13}{\mathrm{cm}}^{-2}$ per QW is deduced, a value ten times larger than for $\mathrm{InGaAs}$ QWs. In contrast, the PL spectra of an $\mathrm{InGaN}∕\mathrm{GaN}$ QW MC do not exhibit such an anticrossing behavior as should be expected from the strong-coupling regime (SCR). By modeling cavity absorption and PL spectra at the resonance, the conditions, in terms of inhomogeneous excitonic broadening, for the observation of the SCR in these nitride MCs are determined.

• Received 10 January 2006

DOI:https://doi.org/10.1103/PhysRevB.73.153305