An optical connection substrate that includes a fiber cavity recessed into a first surface of the optical connection substrate, where the fiber cavity has a plurality of cavity walls and a cavity floor. The optical connection substrate also includes a plurality of fiber receiving grooves recessed into the first surface and a plurality of integrated waveguides disposed within a substrate body. The plurality of cavity walls have an interface cavity wall and the plurality of fiber receiving grooves extend from the interface cavity wall toward the plurality of integrated waveguides in alignment with the plurality of integrated waveguides.