Laser emission from semiconductor microcavities: transition from nonperturbative to perturbative regimes

Summary form only given.We present experimental studies of laser emission in the nonperturbative regime in a GaAs quantum well (QW) microcavity. By tuning the cavity resonance to the low energy side of the inhomogeneous exciton distribution, we are able to achieve laser emission at exciton densities well below the exciton saturation density at which cavity polaritons vanish.