Ignition and formation dynamics of a polariton condensate on a semiconductor microcavity pillar.

We present an experimental study on the ignition and decay of a polariton optical parametric oscillator (OPO) in a semiconductor microcavity pillar. The combination of a continuous-wave laser pump, under quasi-phasematching conditions, and a nonresonant, 2-ps-long pulse probe allows us to obtain the full dynamics of the system. The arrival of the probe induces a blueshift in the polariton emission, bringing the OPO process into resonance with the pump, which triggers the OPO process. We time-resolve the polariton OPO signal emission for more than 1 ns in both real space and momentum space. We fully characterize the emission of the OPO signal with spectral tomography techniques. Our interpretations are backed up by theoretical simulations based on the two-dimensional coupled Gross-Pitaevskii equation for excitons and photons. [ABSTRACT FROM AUTHOR]