Abstract: An optical element comprises a substantially transparent material having opposing first and second transmission surfaces and a substantially flat mounting surface between them, an alignment mark, and an optical coating. The optical element is mounted self-supporting on a substrate with the mounting surface on a mating portion thereof. With the alignment mark aligned to a corresponding mark on the substrate, waveguides on the substrate can be end-coupled by reflection from the first transmission surface. The transmission and mounting surfaces are arranged to position the transmission surfaces at respective orientations relative to the substrate surface so that an optical beam propagating substantially parallel to the substrate surface and entering the optical element through the first transmission surface propagates as an optical beam through the optical element above the mounting surface and exits the optical element through the second transmission surface.

Abstract: An apparatus comprises: a substrate; a photodetector formed on an area of a surface of the substrate; an electrical contact formed on a portion of the photodetector; and a reflector formed over a portion of the photodetector distinct from the portion of the photodetector having the electrical contact formed thereon. The substrate, the photodetector, and the reflector are arranged so that an optical signal to be detected is incident on the photodetector from within the substrate, and at least a portion of the optical signal incident on the photodetector and transmitted thereby on a first pass is reflected by the reflector to propagate through the photodetector for a second pass.