Abstract

The realization of strong nonlinear interactions between individual light quanta (photons) is a long-standing goal in optical science and engineering, being of both fundamental and technological significance. We describe and demonstrate a medium that is nonlinear at the level of individual quanta, exhibiting strong absorption and phase shift for photon pairs while remaining transparent to single photons. The quantum nonlinearity is obtained by coherently coupling slowly propagating photons to strongly interacting atomic Rydberg states in a cold, dense atomic gas. Finally, we will discuss our progress towards realization of integrated quantum photonic systems, based on deterministic coupling of individual atoms and atom-like systems to photonic crystal cavities.

© 2013 Optical Society of America