Abstract: An optical waveguide is formed in an integrated optics chip that includes a substrate formed of an electrooptically active material. The optical waveguide network has an input facet where optical signals may be input to the optical waveguide network and an output facet where optical signals may be output from the optical waveguide network. A structure is located in an upper layer of the substrate to prevent surface waves that propagate in the substrate from cross coupling into the output facet.

Abstract: An integrated optics chip includes an optical waveguide network formed on a surface of an electrooptically active material. The optical waveguide network has an input facet where an optical signal may be input to the optical waveguide network and an output facet where optical signals may be output from the optical waveguide network. One or more trenches is formed in the bottom surface of the surface and arranged to extend into the substrate toward the optical waveguide network to a depth of at least 70% of the thickness. The trenches prevent light rays incident thereon from inside the substrate from propagating to the output facet. In particular, the trenches prevent light scattered at the input facet or from scattering centers in the optical waveguide network from reflecting from the bottom surface of the substrate to the output facet. A cover may be mounted to the top surface of the substrate to provide structural strength to the integrated optics chip.