Femtojoule-scale all-optical latching and modulation via cavity nonlinear optics

We experimentally characterize Hopf bifurcation phenomena at femtojoule energy scales in a multi-atom cavity quantum electrodynamical (cavity QED) system, and demonstrate how such behaviors can be exploited in the design of all-optical memory and modulation devices. The data are analyzed using a semiclassical model that explicitly treats heterogeneous coupling of atoms to the cavity mode. Our results highlight the interest of cavity QED systems for ultra-low power photonic signal processing as well as for fundamental studies of mesoscopic nonlinear dynamics.