Nonlinear switching dynamics in a photonic-crystal nanocavity

We measure the nonlinear switching dynamics of an InP photonic crystal nanocavity for different pulse energies and wavelengths relative to the cavity resonance and observe saturation of the switching contrast and broadening of the switching window. The effects are analyzed by comparison with nonlinear coupled mode theory and explained in terms of large dynamical variations of the cavity resonance. The results are important for applications in optical signal processing and provide insight into the nonlinear optical processes that govern the dynamics of the refractive index and the absorption.