A waveguide substrate comprising: a first surface and a second surface opposite the first surface; an input edge and an output edge; at least one waveguide within the waveguide substrate extending from the input edge to the output edge such that an input end of the at least one waveguide is at the input edge and an output end of the at least one waveguide is at the output edge; at least one input alignment feature within the input edge adjacent to the input end of the at least one waveguide; at least one output alignment feature within the output edge adjacent to the output end of the at least one waveguide, wherein each of the at least one input alignment feature and the at least one output alignment feature is a notch within the input edge and the output edge, respectively, between the first surface and the second surface; and comprising: a first slit opening extending through the waveguide substrate and adjacent to the at least one waveguide at the output edge; and a second slit opening extending through the waveguide substrate at the output edge, wherein the second slit opening is offset from the first slit opening such that the first slit opening and the second slit opening define a connector ferrule at the output edge, and the at least one waveguide is disposed within the connector ferrule; characterized in that the first slit opening and the second slit opening are curved defining a diameter corresponding to the corresponding connector ferrule and the first slit opening and the second slit opening are configured to receive a sleeve that at least partially surrounds the connector ferrule. a first surface and a second surface opposite the first surface; an input edge and an output edge; at least one waveguide within the waveguide substrate extending from the input edge to the output edge such that an input end of the at least one waveguide is at the input edge and an output end of the at least one waveguide is at the output edge; at least one input alignment feature within the input edge adjacent to the input end of the at least one waveguide; at least one output alignment feature within the output edge adjacent to the output end of the at least one waveguide, wherein each of the at least one input alignment feature and the at least one output alignment feature is a notch within the input edge and the output edge, respectively, between the first surface and the second surface; and comprising: a first slit opening extending through the waveguide substrate and adjacent to the at least one waveguide at the output edge; and a second slit opening extending through the waveguide substrate at the output edge, wherein the second slit opening is offset from the first slit opening such that the first slit opening and the second slit opening define a connector ferrule at the output edge, and the at least one waveguide is disposed within the connector ferrule; characterized in that the first slit opening and the second slit opening are curved defining a diameter corresponding to the corresponding connector ferrule and the first slit opening and the second slit opening are configured to receive a sleeve that at least partially surrounds the connector ferrule. a first slit opening extending through the waveguide substrate and adjacent to the at least one waveguide at the output edge; and a second slit opening extending through the waveguide substrate at the output edge, wherein the second slit opening is offset from the first slit opening such that the first slit opening and the second slit opening define a connector ferrule at the output edge, and the at least one waveguide is disposed within the connector ferrule; characterized in that the first slit opening and the second slit opening are curved defining a diameter corresponding to the corresponding connector ferrule and the first slit opening and the second slit opening are configured to receive a sleeve that at least partially surrounds the connector ferrule.