Spatiospectral separation of exceptional points in PT-symmetric optical potentials

Abstract

Non-Hermitian Hamiltonians satisfying parity-time (PT) symmetry reveal unusual physical phenomena related to exceptional points, where the onset of PT symmetry breaking occurs. Here, by permitting dispersive variations in the PT-symmetric potential along the propagation axis of a wave, we show that it is possible to obtain PT-induced exceptional points of spatiospectral separation. As an example, we demonstrate "rainbow nonreciprocity" using a PT-symmetric chirped optical potential.