Bent optical fiber couplers and opto-electrical assemblies formed therefrom

• US 7,802,927 B2
• Filed: 04/30/2009
• Issued: 09/28/2010
• Est. Priority Date: 05/30/2008
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Cable Systems LLC (Corning Incorporated)
• Inventors: Schweiker, Wolfgang Gottfried Tobias, Grzybowski, Richard Robert, Sutherland, James Scott, Hemenway, Brewster Roe Jr., Lewallen, Christopher Paul, Benjamin, Seldon David, Luther, James Phillip
• Primary Examiner(s): HEALY, BRIAN
• Application Number:
  US12/432,799
• Publication Number:
  US 20090297099A1
• Time in Patent Office: 516 Days
• Field of Search: 385/31, 385/32, 385/38, 385/39, 385/42, 385/52, 385/53, 385/88, 385/89, 385/92, 385/94, 385/139, 385/33, 385/34
• US Class Current: 385/88
• CPC Class Codes: G02B 6/02366 Single ring of structures, e.g. "air clad"
• CPC Class Codes: G02B 6/25 Preparing the ends of light guides for coupling, e.g. cutting
• CPC Class Codes: G02B 6/4202 for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/424 Mounting of the optical light guide
• CPC Class Codes: G02B 6/4245 Mounting of the opto-electronic elements
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: G02B 6/4257 having a supporting carrier or a mounting substrate or a mounting plate G02B6/3648 takes precedence
• CPC Class Codes: G02B 6/4266 Thermal aspects, temperature control or temperature monitoring thermal aspect of electrical circuits H05K7/20, H05K5/0213, temperature control in general G05D23/19
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA

Abstract

A bent optical fiber coupler (100) that employs at least one optical fiber (10) is disclosed. The coupler includes a curved optical fiber guide channel (200) having a strong curve. The optical fiber(s) held within the optical fiber guide channel have a bend corresponding to the guide channel curve. The fiber end portions are optionally disposed within a straight fiber guide (160) at a coupler input/output end, which is preferably configured to have a standard connector geometry. Use of nanostructured fibers for the at least one optical fiber allows for strong bends having tight radii of curvature without imparting significant attenuation. Coupler assemblies that include the coupler optically coupled to at least one opto-electronic device (310) are also disclosed.

Claims

1. An optical coupler comprising:

an upper fiber alignment member having a concave surface;

a lower fiber alignment member having a convex surface and a bottom surface defining a coupler output end, wherein the lower and upper fiber alignment members are arranged to form a first fiber guide channel defining a first coupler input/output (I/O) end, and a central curve defined by said convex and concave surfaces; and

at least one optical fiber having an end portion with a proximal end face, wherein at least a portion of the at least one optical fiber is held within and supported by the first fiber guide channel so as to form a bend in the at least one optical fiber corresponding to the central curve, and to position the proximal fiber end face at or near the bottom surface of the lower fiber alignment member so as to define a second coupler I/O end.

2. The optical coupler of claim 1, wherein the at least one optical fiber has an attenuation increase of less than or equal to 5 dB at a wavelength of 1550 nm when subject to one turn around a 10 mm diameter mandrel.

3. The assembly of claim 1, wherein the lower alignment member comprises a heat shield disposed adjacent an inside portion of the fiber bend.

4. The coupler of claim 1, wherein the central curve is a substantially right-angled bend.

5. The coupler of claim 1, wherein said central curve has a bend radius RC wherein 1 mm≦

RC≦

15 mm.

6. The coupler of claim 1, further comprising a divider member arranged within the first fiber guide channel to divide the channel into a plurality of channels each having at least one optical fiber.

7. The coupler of claim 1, wherein the bend formed in the at least one optical fiber does not cause an attenuation of greater than 0.1 dB.

8. The coupler of claim 1, further comprising an optical detector arranged adjacent an outside portion of the optical fiber bend so as to detect light exiting the at least one optical fiber at the bend.

9. The coupler of claim 1, wherein the proximal end face of the at least one optical fiber is oblique to a center line of the at least one optical fiber.

10. The coupler of claim 1, wherein the proximal end face of the at least one optical fiber includes an integrally formed lens.

11. An opto-electronic assembly, comprising:

the coupler of claim 1; and

an opto-electronic device optically coupled the second I/O end of the coupler, wherein the opto-electronic device comprises at least one device selected from the group of devices comprising;

an optical detector, an optical light source and at least one vertical-cavity surface-emitting laser (VCSEL).

12. The assembly of claim 11, comprising a plurality of staggered lower alignment members configured to support a corresponding plurality of optical fibers so that the optical fiber end faces are staggered relative to one another at the second I/O end.

13. A method of forming an optical coupler comprising:

providing at least one optical fiber having an end portion with a proximal end face;

holding the at least one optical fiber between respective concave and convex surfaces of upper and lower fiber alignment guides so as to form and support a bend in the at least one optical fiber, wherein the bend formed in the at least one optical fiber does not cause an attenuation of greater than 0.1 dB.

14. The method of claim 13, wherein the at least one optical fiber has an attenuation increase of less than or equal to 5 dB at a wavelength of 1550 nm when subject to one turn around a 10 mm diameter mandrel.

15. The method of claim 13, further comprising:

bending the at least one optical fiber over the convex surface of the lower alignment guide;

applying a curable adhesive layer to the convex surface and the at least one optical fiber so as to form the upper alignment member; and

curing the curable adhesive layer.

16. The method of claim 13, further comprising:

at least partially bending the at least one optical fiber over the convex surface of the lower alignment guide; and

irradiating the bend in the at least one optical fiber with a laser beam prior to holding the at least one optical fiber between the respective concave and convex surfaces of the upper and lower fiber alignment guides.

17. The method of claim 13, further including laser processing the proximal end face of the at least one optical fiber as the at least one optical fiber is being held between the respective concave and convex surfaces of the upper and lower fiber alignment guides.

18. The method of claim 13, further comprising mechanically polishing the proximal end face of the at least one optical fiber, using a mechanical polisher, as the at least one optical fiber is being held between the respective concave and convex surfaces of the upper and lower fiber alignment guides.

19. An optical coupler comprising:

a coupler body having a top surface, bottom surface and a central fiber guide channel formed in the top surface, the central fiber guide channel sized to accommodate a fiber ribbon and having a convex curved surface and input and output ends;

an optical fiber guide formed integral with the coupler body and arranged at the channel output end of central fiber guide channel and having a plurality of holes open to the bottom surface and defining an input/output (I/O) end;

a fiber ribbon comprising a plurality of optical fibers with respective end portions and proximal end faces, with the fiber ribbon disposed in the central fiber guide channel so as to have a bend, and to position end portions of the optical fibers within the fiber guide holes so that the fiber end faces are disposed at the coupler I/O end, wherein the optical fibers have an attenuation increase of less than or equal to 5 dB at a wavelength of 1550 nm when subject to one turn around a 10 mm diameter mandrel; and

a clamp having a concave surface that covers the fiber ribbon within the central fiber guide channel and that serves to secure the fiber ribbon therein.

20. A coupler assembly, comprising:

the coupler of claim 19, wherein the coupler body comprises at least two alignment holes in the bottom surface;

an opto-electronic device optically coupled to the I/O end; and

an alignment structure having at least two alignment pins that engage the at least two alignment holes so as to facilitate aligning the coupler to the opto-electronic device.

21. A method of producing an optical coupler, comprising:

providing an optical fiber with an end portion;

disposing the optical fiber in a central fiber guide channel of a coupler body so as to form a bend in the optical fiber;

positioning the fiber end portion within a hole of an end fiber guide of the coupler body so that the fiber end portion extends from an end of the end fiber guide; and

laser processing the fiber end portion that extends from the end of the end fiber guide to form a fiber end face.

22. The method of claim 21, wherein the laser processing further comprises forming the fiber end face so as to be flush with the end fiber guide end.