All-optical signal processing using InP photonic-crystal nanocavity switches

In this paper, we present recent progress in experimental characterization of InP photonic-crystal nanocavity switches. Pump-probe measurements on an InP PhC H0 cavity show large-contrast ultrafast switching at low pulse energy. At large pulse energies, a large resonance shift passing across the probe leads to pulse broadening. In addition, high-frequency carrier density oscillations can be induced, leading to pulse splitting. Excellent agreements between simulations and experiments are obtained when employing a carrier rate equation model containing three relaxation times, accounting for the joint effects of fast carrier diffusion, slow surface and bulk recombination. Utilizing the simple InP PhC nanocavity structure, we successfully demonstrate 10-Gb/s RZ-OOK all-optical modulation with low energy consumption.