Using a ray-optics model, we analyze the guided modes of a slab waveguide that consists of a low-index layer sandwiched between two photonic bandgap structures. Normalized band diagrams and dispersion curves for the TE and TM waves are investigated in detail, and a nomenclature system for the guided modes based on the mode-field patterns in the waveguide is proposed. The cutoff conditions and the confinement factors of the modes are discussed. The effects of varying the physical parameters of the waveguide on the dispersion characteristics of the modes are also analyzed.
J. O. VasseurBahram Djafari‐RouhaniL. DobrzyńskiAbdellatif AkjoujJ. Zemmouri