An optical coupler and method of assembly are described that provide efficient coupling from the photonic integrated circuit (PIC) waveguide layer to external components, such as optical fibers, VCSELs, photodetectors, and gain blocks, among others. The optical coupler includes a PIC that can be supported by a printed circuit board, an optoelectronic transducer supported by the PIC that can convert between optical signals and corresponding electrical signals, and a coupled waveguide assembly. The coupled waveguide assembly includes a low-index waveguide, a high-index waveguide, and a reflective surface that changes a pathway of the optical signals to direct the optical signals from the optoelectronic transducer into the low-index waveguide or from the low-index waveguide into the optoelectronic transducer.