Guiding mechanisms and dispersion engineering in photonic crystal waveguides

We examine the guiding mechanism of photonic crystal (PC) waveguide modes through the properties of their evanescent fields in the photonic crystal cladding, allowing an unambiguous definition of gap-guided and index-guided modes. We show that the ability to tailor the dispersion of PC waveguide modes depends on the properties of these fields. Our analysis suggests that the photonic crystal's lattice type can be used to maximize the region of the Brillouin zone where PC waveguide modes can be dispersion engineered.