Optical junction apparatus and methods employing optical power transverse-transfer

1. A method for fabricating an optical apparatus, comprising:

forming a first transmission optical waveguide on a waveguide substrate, the first transmission optical waveguide comprising a planar optical waveguide formed on the waveguide substrate and having an optical junction region, the waveguide substrate and the first transmission optical waveguide together comprising a first optical transmission subunit;

fabricating a second optical transmission subunit comprising a second transmission optical waveguide having an optical junction region, the first optical transmission subunit and the second optical transmission subunit comprising discrete subunits;

adapting the first transmission optical waveguide or the second transmission optical waveguide for enabling substantially adiabatic transverse-transfer of optical power between the optical waveguides at the respective optical junction regions; and

assembling the first optical transmission subunit with the second optical transmission subunit, thereby forming the optical apparatus.

2. The method of claim 1 , further comprising structurally adapting the first optical transmission subunit or the second optical transmission subunit for assembly of the first optical transmission subunit with the second optical transmission subunit.

3. The method of claim 1 , further comprising structurally adapting the first optical transmission subunit or the second optical transmission subunit for positioning, upon assembly of the first optical transmission subunit with the second optical transmission subunit, the respective optical junction regions for enabling transverse-transfer of optical power between the optical waveguides.

4. The method of claim 1 , wherein the first transmission optical waveguide or the second transmission optical waveguide comprises a low-modal-index optical waveguide.

5. The method of claim 1 , wherein the second optical transmission subunit comprises a second transmission planar optical waveguide formed on a corresponding waveguide substrate.

6. The method of claim 5 , further comprising adapting the first transmission optical waveguide or the second transmission optical waveguide at a distal end thereof for enabling end-transfer of optical power to an optical fiber.

7. A method for fabricating an optical transmission subunit, comprising:

forming a transmission optical waveguide on a waveguide substrate, the transmission optical waveguide comprising a planar optical waveguide formed on the waveguide substrate and having an optical junction region, the waveguide substrate and the transmission optical waveguide together comprising the optical transmission subunit; and

adapting the transmission optical waveguide for enabling transverse-transfer of optical power at the optical junction region between the transmission optical waveguide and another transmission optical waveguide,

wherein the optical transmission subunit comprises a discrete subunit relative to another optical transmission subunit comprising the other transmission optical waveguide.

8. The method of claim 7 , further comprising structurally adapting the optical transmission subunit for assembly with the other optical transmission subunit.

9. The method of claim 7 , further comprising structurally adapting the optical transmission subunit for positioning the optical junction region and the other transmission optical waveguide for enabling transverse-transfer of optical power between the transmission optical waveguide and the other transmission optical waveguide.

10. The method of claim 7 , further comprising adapting the transmission optical waveguide for enabling substantially adiabatic transverse-transfer of optical power between the transmission optical waveguide and the other transmission optical waveguide at the optical junction region.

11. The method of claim 10 , wherein at least a portion of the transmission optical waveguide comprises a core and lower-index cladding, and at least one transverse dimension of the core or the cladding varies longitudinally along at least a portion of the optical junction region.

12. The method of claim 10 , wherein at least a portion of the transmission optical waveguide comprises a core and lower-index cladding, and a refractive index of the core or the cladding varies longitudinally along at least a portion of the optical junction region.

13. The method of claim 7 , further comprising adapting the transmission optical waveguide for enabling mode-interference-coupled transverse-transfer of optical power between the transmission optical waveguide and the other transmission optical waveguide at the optical junction region.

14. The method of claim 7 , wherein the transmission optical waveguide comprises a low-modal-index optical waveguide.

15. The method of claim 14 , wherein the transmission optical waveguide comprises a silica-based optical waveguide.

16. The method of claim 15 , wherein:

the transmission optical waveguide comprises a core and lower-index cladding;

the core comprises silicon nitride, silicon oxynitride, or doped silica; and

the cladding comprises silica or doped silica.

17. The method of claim 7 , further comprising adapting at least a portion of the transmission optical waveguide for providing a portion of functionality of an optical device assembled with and optically coupled thereto through the other transmission optical waveguide, wherein the optical transmission subunit is mechanically separate from the optical device.