Two-Dimensional Photonic Crystal Waveguides with 60° Bends in a Thin Slab Structure

We experimentally investigated the light propagation characteristics of two-dimensional photonic crystal waveguides, for the first time. The difficulty of fabricating photonic crystals with airholes was reduced by employing a thin slab structure with a GaInAsP high refractive index core, and by employing air and SiO2low index claddings. The light propagation through channels composed of a series of defects in the photonic crystal was observed in the wavelength range 1.51–1.55 µm. Smooth propagation was maintained even beyond 60° channel bends. The wavelength and polarization dependence of propagation characteristics as well as the peculiar scattering of light to space were explained by the photonic band theory.