Integrated optics spectrum analyzer

Abstract From the Canadian patent

An optical waveguide comprises an out-diffused optical waveguide section, an in-diffused optical waveguide section, and a narrow transition region intimately connecting the out-diffused waveguide section and the in-diffused waveguide section. This waveguide structure can decrease the level of in-plane scattering caused by surface irregularities, reduce the difficulty of coupling light into and out of the waveguide the, structure can be made to perform as a transverse magnetic mode filter, and increase the intensity of light focussed into the guide beyond the limits imposed by the optical damage resistance of a strictly in-diffused waveguide.