Grating Assisted InGaAsP/InP Vertical Co-Directional Coupler Filter

We report a novel wavelength selective coupler based upon grating assisted forward coupling between two, non-identical, vertically stacked InGaAsP/InP waveguides. Using a 14.4micron period to provide phasematching between the asynchronous waveguides, we achieve a 3 dB filter bandwidth (FWHM) of 65angstroms with a device length of only 1.0 mm.