Alignment of fiber optic bundle to array waveguide using pins
A device and method for aligning a fiber optic bundle with an array waveguide uses pins that partially extend into both the fiber optic bundle and the array waveguide to achieve course alignment. In one embodiment, the pins are inserted into holes formed by V-grooves in the fiber optic bundle. Finely aligning the fiber optic bundle and the array waveguide may be done by manual adjustment.
The present application is a continuation of U.S. patent application Ser. No. 09/738,686 filed Dec. 15, 2000, entitled “ALIGNMENT OF FIBER OPTIC BUNDLE TO ARRAY WAVEGUIDE USING PINS”. The U.S. patent application Ser. No. 09/738,686 is hereby incorporated herein by reference.
This patent application is related to:
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- U.S. patent application Ser. No. 09/738,799, filed Dec. 15, 2000, entitled “ALIGNMENT OF FIBER OPTIC BUNDLE TO ARRAY WAVEGUIDE USING AN EPOXY”; and U.S. Pat. No. 6,628,865, filed Dec. 15, 2000, and issued Sep. 30, 2003, entitled “ALIGNMENT OF OPTICAL FIBERS TO AN ETCHED ARRAY WAVEGUIDE”.
1. Field of the Invention
The present application is a continuation of U.S. patent application Ser. No. 09/738,686 filed Dec. 15, 2000, entitled “ALIGNMENT OF FIBER OPTIC BUNDLE TO ARRAY WAVEGUIDE USING PINS”. The U.S. patent application Ser. No. 09/738,686 is hereby incorporated herein by reference.
The described invention relates to the field of optics. In particular, the invention relates to coupling a fiber optic bundle to a planar photonic structure, such as an array waveguide (“AWG”).
2. Description of Related Art
Fiber optic bundles and AWGs are both used for propagating light. A fiber optic bundle has multiple optical fibers for propagating light, and an AWG has multiple channels for propagating light within. Coupling a fiber optic bundle to an AWG, however, is not easy. Manual alignment requires detecting and maximizing light connectivity between the fiber optic bundle and the AWG. Once a good connection is obtained, permanently fixing the alignment is required.
There are several ways of improving alignment between a fiber optic bundle and an AWG. In some cases, quick coarse alignment is followed up with finely aligning the fiber optic bundle and AWG afterwards.
Typical epoxies such as that used in prior art
An epoxy having a silicate content of over 70% by volume has been found to reduce shrinkage. Additionally, the high silicate content makes the epoxy very viscous allowing for manual alignment being maintained after being achieved. Thus, alignment of the termination head 140 and the AWG 142 can be achieved without significant post-bond shrinkage as the epoxy is cured by heat or other methods.
Raising the silicate content of the epoxy to up to 90% by volume reduces the post-bond shrinkage even more. However, as the silicate content is increased, the sheer strength of the bond is reduced, so a balancing between post-bond shrinkage and sheer strength should be performed.
The alignment method using the high viscosity epoxy described provides a robust bond area for achieving and maintaining alignment between the fiber optic bundle and the AWG. Additionally, a gel having a refractive index matching the optical fibers and the AWG channels may be dispensed between the fiber optic bundle and the AWG. This helps to prevent light from scattering at an air gap between the fiber optic bundle and the AWG.
The pins 200 of the fiber optic bundle fit snugly into the recesses 202 of the AWG to provide coarse alignment. Additional manual adjustment to more finely align the fiber optic bundle to the AWG may be performed.
The one retainer 300 is placed over the V-grooves on the AWG 320 to sandwich the optical fibers between the retainer 300 and the AWG 320. The optical fibers come to rest within the V-grooves of the AWG 320. The ends of the optical fibers 322 are butted up against the ends of the AWG's V-grooves 324.
The interlocking compatibility between the retainer 300 and the V-grooves of the AWG 320 provide for quick coarse alignment of the optical fibers with the channels 350 of the AWG. Manual adjustment may then be performed to more finely align the optical fibers with the AWG.
In one embodiment, over-etching the AWG provides for a better ability to manually align the optical fibers and the AWG afterwards. As previously described, gel or epoxy having a refractive index matching the optical fibers and the channels of the AWG can be dispensed between the retainer and AWG.
Thus, a device and method of aligning optical fibers in a fiber optic bundle to a waveguide is disclosed. However, the specific embodiments and methods described herein are merely illustrative. Numerous modifications in form and detail may be made without departing from the scope of the invention as claimed below. Rather, the invention is limited only by the scope of the appended claims.
Claims
1-15. (canceled)
16. A device comprising:
- a fiber optic bundle having a termination block;
- an array waveguide positioned adjacent to the termination block;
- pins each partially extending into both the termination block and the array waveguide; and
- a cured epoxy that bonds the termination block to the array waveguide.
17. The device of claim 16, wherein the termination block comprises two silicon substrates having etched grooves in them, and the pins partially extend into holes formed by placing the two etched silicon substrates together.
18. The device of claim 16, wherein the pins partially into etched recesses in the array waveguide.
19. A method comprising:
- inserting one or more selected from pins, rods, and dowels, into one or more holes formed in both a fiber optic bundle and an array waveguide; pressing the fiber optic bundle and the array waveguide together so that the one or more selected from the pins, rods, and dowels, extend into both the fiber optic bundle and the array waveguide;
- applying an epoxy to bond the fiber optic bundle to the array waveguide; and
- curing the epoxy.
20. The method of claim 19, further comprising, prior to said curing the epoxy, finely aligning optical fibers in the fiber optic bundle with channels of the array waveguide.
21. The method of claim 20, wherein said finely aligning the optical fibers in the fiber optic bundle with the channels of the array waveguide comprises performing manual adjustment.
22. The method of claim 19, wherein said inserting the one or more selected from the pins, rods, and dowels, into the one or more holes formed in the fiber optic bundle comprises inserting the one or more selected from the pins, rods, and dowels, into one or more holes formed by placing two etched substrates together.
23. The method of claim 19, wherein said inserting the one or more selected from the pins, rods, and dowels, into the one or more holes formed in the array waveguide comprises inserting the one or more selected from the pins, rods, and dowels, into one or more etched holes in the array waveguide.
24. A method comprising:
- coarsely aligning a fiber optic bundle with an array waveguide by: inserting pins into holes formed in an end of a fiber optic bundle; inserting opposite ends of the pins into an array waveguide; and pressing the fiber optic bundle and the array waveguide together; and
- finely aligning the fiber optic bundle with the array waveguide after said coarsely aligning the fiber optic bundle with the array waveguide.
25. The method of claim 24, further comprising:
- applying an epoxy between the fiber optic bundle and the array waveguide; and
- after said finely aligning, curing the epoxy to bond the fiber optic bundle and the array waveguide.
26. The method of claim 24, wherein said inserting the pins into the holes formed in the end of the fiber optic bundle comprises inserting the pins into holes formed by placing two etched substrates together.
27. The method of claim 24, wherein said inserting the opposite ends of the pins into the array waveguide comprises inserting the ends of the pins into etched holes in the array waveguide.
28. A method comprising:
- providing an array waveguide having a material located in positions corresponding to recesses to accommodate pins where the material is different than other materials of the array waveguide; and
- selectively removing the material to form the recesses to accommodate the pins.
29. The method of claim 28, wherein said selectively removing the material comprises selectively etching the material.
30. The method of claim 28, further comprising introducing pins into both the recesses and into holes in a fiber optic bundle.
31. A method comprising:
- placing optical fibers in etched grooves in a first silicon substrate;
- placing a second silicon substrate having etched grooves therein such that the optical fibers are sandwiched between the etched grooves of the first and second silicon substrates and such that other etched grooves of the first and second silicon substrates form holes.
32. The method of claim 31, further comprising inserting pins into the holes.
33. The method of claim 31, further comprising etching the other etched grooves of the first and second silicon substrates.
Type: Application
Filed: Apr 8, 2005
Publication Date: Aug 18, 2005
Inventor: Douglas Crafts (San Jose, CA)
Application Number: 11/102,495