Properties of the slab modes in photonic crystal optical waveguides

We show that by placing a slab of semiconductor material between two photon ic bandgap (PBG) mirrors, waveguide modes at frequencies out of the PBC; ca n he obtained. These modes are similar to the modes of a conventional diele ctric slab waveguide. Using these modes, we can obtain very good coupling b etween a PEG waveguide and a dielectric slab waveguide with similar slab pr operties. We discuss the properties of these slab modes and outline the gui deline for the optimization elf the PRC waveguides based on these propertie s.