Dispersion Relation of InGaN Cavity Polaritons Measured by Angle-Resolved Photoluminescence

Photoluminescence (PL) properties in a strong exciton-photon coupling regime are investigated using an InGaN quantum well microcavity. In angle-resolved PL measurements, we observe the dispersion of upper and lower polariton branches with Rabi splitting at room temperature.

Cavity polaritons are quasi-particles that are created by a strong exciton-photon interaction in a semiconductor quantum well (QW) microcavity [1]. In recent years, much attention has been directed to the behavior of these cavity polaritons as composite bosons at sufficiently small densities. One area of interest relates to polariton devices that employ bosonic behavior, such as the threshold-less laser called a polariton laser [2]–[5]. All of the polaritons will recombine at a final state of with a gain as a result of certain scattering processes, and then coherent light will be emitted from the polaritons in that state. To achieve these devices and room temperature operation, we have to choose materials that have a large oscillator strength and a large exciton binding energy [6]–[7].