Microfabrication method for optical components
A ferrule mold having a reverse-image of a through-hole array for optical fibers is formed. A non-polymeric ferrule material is deposited in the reverse-image mold, followed by removing the mold to create a multi-fiber connector ferrule having at least two fiber through-holes. An optical fiber is inserted in each through-hole until each fiber endface is positioned approximately even with a connection surface of the ferrule. A fiber recess for each of the optical fibers is formed such that each fiber is recessed from the multi-fiber ferrule connection surface by a distance of at least 0.1 micron. The recess may be formed by differential polishing of the non-polymeric ferrule and endfaces of the optical fibers. Alternatively, a layer of spacer material may be deposited over the multi-fiber ferrule connection surface. An antireflection coating is deposited over the ends of the recessed fibers.
1. A high-density, recessed-fiber, multi-fiber optical connector component made by a microfabrication method, comprising: a non-polymeric optical connector ferrule having a front surface, the optical connector ferrule made from a ferrule mold having a reverse-image through-hole array for optical fibers, said through-hole array including at least two through-holes, each through-hole dimensioned and configured for holding and aligning a single optical fiber; an optical fiber with a fiber endface, positioned in each of said fiber through-holes; an antireflection coating deposited over said the optical fiber endfaces; a fiber recess formed for each of the optical fibers by 1) differential polishing of said non-polymeric ferrule front surface and the endface of the optical fibers, or 2) depositing a layer of spacer material over a portion of the non-polymeric ferrule front surface; wherein a contact surface of the optical connector is separated from the antireflection coating on the fiber endfaces by a distance of at least 0.1 micron; wherein said through-holes are formed at a through-hole tilt angle with respect to the surface normal of said front surface of said non-polymeric optical connector ferrule; and wherein the ferrule front surface has a front surface tilt angle with respect to a direction of connection of the multi-fiber optical connector component such that adjacent optical fiber endfaces are positioned at different elevations relative to each other with respect to the direction of connection.
2. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 1 , wherein the ferrule mold material is a silicon-based material.
3. The recessed-fiber, multi-fiber optical connector component as recited in claim 1 , wherein said non-polymeric optical connector ferrule material is a metal.
4. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 3 , wherein said metal ferrule material is deposited by an electrodeposition technique.
5. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 1 , wherein through-holes patterns in two orthogonal directions have two scaling factors, the two scaling factors being related to each other by the cosine of said tilt angle.
6. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 1 , wherein said optical fibers are single mode optical fibers.
7. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 1 , further comprising one or more guide pin through-holes or guide pins formed in said non-polymeric optical connector ferrule.
8. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 1 , further comprising a pedestal connected to said non-polymeric optical connector ferrule.
9. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 8 , wherein said guide pin through-holes include one or more channels for accommodating dust or other contamination.
10. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 8 , wherein said guide pin through-hole wall is a deformable spring-like structure.
11. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 1 , wherein said fiber through-holes have a funnel-shaped expansion at a side opposite from said front surface of non-polymeric connector ferrule.
12. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 8 , wherein at least one guide pin through-hole has an elongated, elliptical cross-sectional profile.
13. A high-density, recessed-fiber, multi-fiber optical connector component comprising: a non-polymeric optical connector ferrule having a front surface and a through-hole array for optical fibers, the through-hole array including at least two through-holes, each through-hole dimensioned and configured for holding and aligning a single optical fiber; an optical fiber with a fiber endface, positioned in each of said fiber through-holes; an antireflection coating deposited over said fiber endfaces; a fiber recess formed for each of the optical fibers by 1) differential polishing of said non-polymeric ferrule front surface and an end of the optical fibers, or 2) depositing a layer of spacer material over said non-polymeric ferrule front surface, wherein a contact surface of the optical connector is separated from the antireflection-coated fiber endfaces by a distance of at least 0.1 micron; wherein said fiber through-holes are formed at a fiber through-hole tilt angle with respect to the surface normal of said front surface of said non-polymeric optical connector ferrule; and wherein the ferrule front surface has a front surface tilt angle with respect to a direction of connection of the multi-fiber optical connector component such that adjacent optical fiber endfaces are positioned at different elevations relative to each other with respect to the direction of connection.
14. The recessed-fiber, multi-fiber optical connector component as recited in claim 13 , wherein said non-polymeric connector ferrule material is a metal.
15. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 14 , wherein said metal ferrule material is deposited by an electrodeposition technique.
16. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 14 , wherein through-holes patterns in two orthogonal directions have two scaling factors, the two scaling factors being related to each other by the cosine of said tilt angle.
17. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 13 , wherein said optical fibers are single mode optical fibers.
18. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 13 , further comprising guide pin through-holes or guide pins formed in said non-polymeric optical connector ferrule.
19. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 13 , further comprising a pedestal connected to said non-polymeric optical connector ferrule.
20. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 18 , wherein said guide pin through-holes include one or more channels for accommodating dust or other contamination.
21. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 18 , wherein said guide pin through-hole incudes a wall having a deformable spring-like structure.
22. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 13 , wherein said fiber through-holes have a funnel-shaped expansion at a side opposite from said front surface of non-polymeric connector ferrule.
23. The high-density, recessed-fiber, multi-fiber optical connector component as recited in claim 18 , wherein at least one said guide pin through-hole has an elongated, elliptical cross-sectional profile.