A molded waveguide side-facet coupler to facilitate an optical connection between optical side-facets and a fiber optic connector is disclosed. Instead of molding the side-facet coupler with the external mounting surface disposed on an external surface of the mold, the mold for the side-facet coupler is provided such that the mounting surface of the side-facet coupler is provided as a molded internal recess surface. The moldable material for the side-facet coupler is disposed around a recess core that is part of the mold, thereby forming a unitary component having at least one internal recess surface for providing an external mounting surface for the side-facet coupler. As the molded material cures around the core structure, the external surfaces of the unitary component pull away from internal surfaces of the mold, and shrink around the core structure. Thus, the internal recess surface of the unitary component is formed within narrower, repeatable tolerances.