Photon lasing inGaAsmicrocavity: Similarities with a polariton condensate

Abstract

We study experimentally the lasing regime of a $\mathrm{GaAs}$ based microcavity sample under strong optical pumping. The very same sample exhibits the strong coupling regime at low excitation power with a Rabi splitting as large as $15\mathrm{meV}$. We show that some features which may be considered as experimental evidence of polariton Bose-Einstein condensation are also observed in the weak coupling regime when the cavity is behaving as a regular photon laser. In particular, the emission pattern in the lasing regime displays a sharp peak near the energy minimum followed by a Boltzmann distribution at higher energies.