A circuitized substrate (e.g., PCB) including an internal optical pathway as part thereof such that the substrate is capable of transmitting and/or receiving both electrical and optical signals. The substrate includes an angular reflector on one of the cladding layers such that optical signals passing through the optical core will impinge on the angled reflecting surfaces of the angular reflector and be reflected up through an opening (including one with optically transparent material therein), e.g., to a second circuitized substrate also having at least one internal optical pathway as part thereof, to thus interconnect the two substrates optically. A method of making the substrate is also provided.