Abstract: An optical apparatus comprises: a semiconductor substrate; a semiconductor optical device integrally formed on the substrate and having a device end face; and a low-index planar optical waveguide integrally formed on the semiconductor substrate at the device end face. The waveguide is end-coupled at its proximal end to the optical device through the device end face and is arranged so as to comprise a waveguide mode converter. The waveguide is arranged at its distal end to transmit or receive an optical signal through its distal end to or from another low-index optical waveguide end-coupled with the integrally-formed waveguide and assembled with the integrally-formed waveguide, optical device, or substrate. The optical apparatus can further comprise a discrete low-index optical waveguide assembled with the integrally-formed waveguide, optical device, or substrate so as to be end-coupled with the integrally-formed waveguide at its distal end.

Abstract: An optical apparatus comprises a semiconductor optical device waveguide formed on a semiconductor substrate, and an integrated end-coupled waveguide formed on the semiconductor substrate. The integrated waveguide may comprise materials differing from those of the device waveguide and the substrate. Spatially selective material processing may be employed for first forming the optical device waveguide on the substrate, and for subsequently depositing and forming the integrated end-coupled waveguide on the substrate. Spatially selective material processing enables accurate spatial mode matching and transverse alignment of the waveguides, and multiple device waveguides and corresponding integrated end-coupled waveguides may be fabricated concurrently on a common substrate on a wafer scale.