Reversible nonreciprocity in photonic structures infiltrated with liquid crystals

We demonstrate how to achieve reversible nonreciprocal optical response in a periodic photonic structure with a pair of defects, one of them being a nonlinear liquid crystal defect layer. The twin defect layers structure is symmetric at low intensity and becomes asymmetric above a power threshold corresponding to the optical reordering of the liquid crystal. We show that nonreciprocal effects can be reversed by changing the wavelength as a consequence of the defect mode dependent light localization inside the structure.The work has been supported by the Australian Research Council project DP0771218 and the the France-Australia cooperation project 21337 of CNRS