Cavity switching: A novel resource for solid-state quantum optics

We present switching experiments performed on pillar microcavities containing a collection of quantum dots (QDs). Switching events are probed using QD luminescence, after ultrafast optical injection of free carriers. We observe large switching amplitudes (by as much as 20 linewidths), as well as differential switching of the pillar modes under inhomogeneous pumping. Through transient coupling of QDs with a cavity mode, cavity switching is used for the first time to generate ultrashort (down to 4ps!) pulses of spontaneous emission. Beyond this application, cavity switching can be used more generally to control CQED effects in the time domain.