Investigating wavelength bandwidth of orthogonal lattice waveguide for circular defect in two-dimensional photonic crystal (CirD) lasers

To achieve wavelength division multiplexing of optical communications for short distances, we have theoretically investigated a photonic crystal waveguide we call an orthogonal lattice waveguide (OLW), which may have a communication wavelength bandwidth of about 20 nm. In this paper, we fabricate CirD laser structures with air-cladding layers and OLWs of different cavity radii. We confirm that the light emitted from the OLW is the light generated in the cavity. OLW has a wavelength bandwidth of about 20 nm, which agrees with the results of our previous theoretical study. The wavelength shift is about 4 nm when the radius of the circular defect cavity increases by 0.01 a , where a is the lattice constant.