Excitability and self-pulsing in a photonic crystal nanocavity

Bistability, excitability, and self-pulsing regimes in an InP-based two-dimensional (2D) photonic crystal nanocavity with quantum wells as an active medium are investigated. A resonant cw beam is evanescently coupled into the cavity through a tapered microfiber. In such conditions, we show that the cavity exhibits class II excitability, which arises from the competition between a fast electronic nonlinear effect, given by carrier-induced refractive index change, and slow thermal dynamics. Multiple perturbation-pulse experiments allow us to measure the refractory time ("dead time" between two excitable pulses) of the excitable nanocavity system.