The capture, hold and forward release of an optical pulse from a dynamic photonic crystal nanocavity.

We develop a silicon photonic crystal nanocavity device capable of performing targeted optical pulse capture and release via distinct ports on demand, based on dynamic Q factor control. The capture of 4 ps pulses and their release up to 332 ps later is directly observed by time-resolved measurements of the energy behaviour in both the nanocavity and emitted from the release port. We also discuss how the behaviour of excited free carriers dictates the performance of such dynamic devices.