Near field mapping of coupled photonic crystal microcavities

We make use of near-field microscopy to image the coupling between two adjacent photonic crystal microcavities A special design of the photonic structures is adopted with selective coupling between different modes having orthogonal spatial extensions Spatial delocalization of coupled-cavity optical modes is found whenever the frequency matching condition is fulfilled On the contrary, in case of large detuning, the modes are localized in each microcavity