Practical and theoretical modal analysis of photonic ctystal waveguides

A stage-by-stage analysis of light propagation around a 90° corner in a two-dimensional photonic crystal waveguide was discussed. The coupling efficiency between the conventional ridge waveguide and the photonic crystal waveguide was quantified using a series of different samples. A 90% bending efficiency was demonstrated by the transmission spectra. It was suggested that the efficient transmission around the sharp bends in photonic crystal waveguides can be achieved for leaky modes above the light line with short photonic crystal sections.