Bipolariton laser emission from a GaAs microcavity

Biexciton emission properties were studied in a single GaAs quantum well semiconductor planar microcavity by photoluminescence measurements at low temperatures. At high pump intensity a bipolariton emission appears close to the lower polariton mode. This new mode appears when we detune the cavity resonance out of the lower polariton branch, showing a laser-like behavior. Very small linewidths were measured, lying below 110 μeV and 150 μeV for polariton and bipolariton emission respectively. The input/output power (I/O) measurements show that the bipolariton emission has a weaker coupling efficiency compared to previous results for polariton emission. Varying the pump laser polarization, we were able to show the selection rules for the biexciton particle creation in the quantum well. Simultaneous photoluminescence and near-field measurements show that the polariton and bipolariton emission are spectrally and spatially separated.