Propagation characteristics of one-dimensional photonic crystal slab waveguides and radiation loss

Abstract

We present a type of slab waveguide structure, which is composed of one-dimensional photonic crystal. We calculated the dispersion relations and radiative loss ratio for air-bridge and $\mathrm{Si}{\mathrm{O}}_{2}$ cladding waveguide structures. The calculations show that the dispersion relations of the proposed waveguide are greatly different from those of the usual index-guided waveguide structure, and then predict the existence of small-group velocity modes. Although the small-group velocity modes are above the light line, the numerical results indicate that they have a small radiation-loss rate for large slab thicknesses, even above the light line of cladding material.