Theoretical investigation on communication bandwidth of an orthogonal symmetry-based photonic crystal waveguide for wavelength division multiplexing

Abstract To realize wavelength division multiplexing for high-capacity optical communications, we theoretically investigate the properties of a photonic crystal waveguide structure in which a row of air holes is displaced by a/2 (a is the lattice constant). We calculate transmission loss and coupling efficiency to circular defect cavities of this waveguide structure, which we call an orthogonal lattice waveguide (OLW). The communication bandwidth of the OLW is estimated to be about 20 nm, which is twice that of the conventional line-defect (W1) waveguide. This result indicates that improvements in characteristics of the wavelength division multiplexing are expected by using the OLW instead of W1.