Etched-facet semiconductor optical component with integrated end-coupled waveguide and methods of fabrication and use thereof

An optical apparatus, comprising:

• a semiconductor substrate;
• a semiconductor optical device integrally formed on the substrate and having a device end face;
• a low-index planar optical waveguide integrally formed on the semiconductor substrate at the device end face and end-coupled at its proximal end to the optical device through the device end face, the integrally-formed waveguide being arranged so as to comprise a waveguide mode converter, the integrally-formed waveguide being arranged at its distal end to transmit or receive an optical signal through its distal end to or from a discrete low-index optical waveguide end-coupled with the integrally-formed waveguide and assembled with the integrally-formed waveguide, with the optical device, or with the substrate;
• and
• a reflective optical coating between the substrate and at least a proximal portion of the integrally-formed waveguide,
• wherein the semiconductor substrate, the semiconductor optical device, and the low-index planar optical waveguide together form a single monolithically integrated optical structure.

An optical apparatus, comprising:

• a semiconductor substrate;
• a semiconductor optical device integrally formed on the substrate and having an etched device end face;
• and
• a low-index planar optical waveguide integrally formed on the semiconductor substrate at the etched device end face and end-coupled at its proximal end to the optical device through the etched device end face, the integrally-formed waveguide being arranged so as to comprise a waveguide mode converter, the integrally-formed waveguide being arranged at its distal end to transmit or receive an optical signal through its distal end to or from a discrete low-index optical waveguide end-coupled with the integrally-formed waveguide and assembled with the integrally-formed waveguide, with the optical device, or with the substrate,
• wherein:
• the semiconductor substrate, the semiconductor optical device, and the low-index planar optical waveguide together form a single monolithically integrated optical structure;
• and
• at least a portion of the etched device end face is curved in the horizontal dimension.

A method for fabricating an optical apparatus, the method comprising:

• integrally forming a low-index planar optical waveguide on a semiconductor substrate at an etched end face of a semiconductor optical device integrally formed on the semiconductor substrate;
• etching the device end face so as to leave an outwardly protruding portion extending along the substrate from a bottom portion of the etched device end face beneath a proximal portion of the integrally-formed waveguide;
• and
• forming at least one layer of the end-coupled waveguide so that it decreases in thickness toward the etched device end face, the outwardly protruding portion of the etched device end face and the decreasing layer thickness together yielding a desired layer surface profile for at least one layer of the integrally-formed end-coupled waveguide,
• wherein:
• the integrally-formed waveguide is end-coupled at its proximal end to the optical device through the etched device end face;
• the integrally-formed waveguide is arranged so as to comprise a waveguide mode converter;
• the integrally-formed waveguide is arranged at its distal end to transmit or receive an optical signal through its distal end to or from a discrete low-index optical waveguide end-coupled with the integrally-formed waveguide and assembled with the integrally-formed waveguide, with the optical device, or with the substrate;
• and
• the semiconductor substrate, the semiconductor optical device, and the low-index planar optical waveguide together form a single monolithically integrated optical apparatus.

A method for fabricating an optical apparatus, the method comprising:

• integrally forming a low-index planar optical waveguide on a semiconductor substrate at an end face of a semiconductor optical device integrally formed on the semiconductor substrate;
• and
• forming a reflective optical coating between the substrate and at least a proximal portion of the integrally-formed waveguide,
• wherein:
• the integrally-formed waveguide is end-coupled at its proximal end to the optical device through the device end face;
• the integrally-formed waveguide is arranged so as to comprise a waveguide mode converter;
• the integrally-formed waveguide is arranged at its distal end to transmit or receive an optical signal through its distal end to or from a discrete low-index optical waveguide end-coupled with the integrally-formed waveguide and assembled with the integrally-formed waveguide, with the optical device, or with the substrate;
• and
• the semiconductor substrate, the semiconductor optical device, and the low-index planar optical waveguide together form a single monolithically integrated optical apparatus.

A method for fabricating an optical apparatus, the method comprising integrally forming a low-index planar optical waveguide on a semiconductor substrate at an etched end face of a semiconductor optical device integrally formed on the semiconductor substrate,

• wherein:
• the integrally-formed waveguide is end-coupled at its proximal end to the optical device through the etched device end face;
• the integrally-formed waveguide is arranged so as to comprise a waveguide mode converter;
• the integrally-formed waveguide is arranged at its distal end to transmit or receive an optical signal through its distal end to or from a discrete low-index optical waveguide end-coupled with the integrally-formed waveguide and assembled with the integrally-formed waveguide, with the optical device, or with the substrate,
• the semiconductor substrate, the semiconductor optical device, and the low-index planar optical waveguide together form a single monolithically integrated optical apparatus;
• and
• at least a portion of the etched device end face is curved in the horizontal dimension.

A method comprising transmitting an optical signal between a semiconductor optical device, integrally formed on a semiconductor substrate, and a low-index end-coupled planar optical waveguide, integrally-formed on the semiconductor substrate at an etched device end face, the integrally-formed waveguide being end-coupled at its proximal end to the optical device through the etched device end face, the integrally-formed waveguide being arranged so as to comprise a waveguide mode converter, the integrally-formed waveguide being arranged at its distal end to transmit or receive an optical signal through its distal end to or from a discrete low-index optical waveguide end-coupled with the integrally-formed waveguide and assembled with the integrally-formed waveguide, with the optical device, or with the substrate, wherein the semiconductor substrate, the semiconductor optical device, and the low-index planar optical waveguide together form a single monolithically integrated optical apparatus,

• wherein:
• the etched device end face includes an outwardly protruding portion extending along the substrate from a bottom portion of the etched device end face beneath a proximal portion of the integrally-formed end-coupled waveguide;
• and
• at least one layer of the end-coupled waveguide decreases in thickness toward the etched device end face, the outwardly protruding portion of the etched device end face and the decreasing layer thickness together yielding a desired layer surface profile for at least one layer of the integrally-formed end-coupled waveguide.