Artificial magnetism and anticrossing interaction in photonic crystals and split-ring structures

In this paper, the authors conduct a study of artificial magnetism and anticrossing interaction that arise in photonic crystals and split-ring structures. The magnetic activity comes from localization of fields in photonic crystals with large dielectric contrast as well as in split-ring structures with the defectlike resonance. Both structures exhibit similar dispersion features near the resonance, whose effective permeability can be described in terms of the Lorentz-type oscillators. In particular, strong magnetic response is accompanied with the anticrossing interaction between the two fundamental frequency branches. This feature is characterized by a simple dynamic model which incorporates the coupling between a free and a localized photon state and illustrated with the transition of mode patterns where the fields mutually exchange their localization nature as the wave number changes.