Cables with bend insensitive optical fibers

• US 8,224,140 B2
• Filed: 12/11/2009
• Issued: 07/17/2012
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Cable Systems LLC (Corning Incorporated)
• Inventors: Hurley, William C.
• Primary Examiner(s): Petkovsek, Daniel
• Application Number:
  US12/636,044
• Publication Number:
  US 20110142403A1
• Time in Patent Office: 949 Days
• Field of Search: 385100-114
• US Class Current: 385/104
• CPC Class Codes: B29D 11/00663 Production of light guides
• CPC Class Codes: G02B 6/02395 Glass optical fibre with a protective coating, e.g. two layer polymer coating deposited directly on a silica cladding surface during fibre manufacture G02B6/02052, G02B6/02057, G02B6/024, G02B6/032, G02B6/105, G02B6/14 take precedence; coating on fibre gratings G02B6/02104; multilayer core or cladding G02B6/036; reinforcing splice joints G02B6/2558; optical cables, i.e. comprising protective structures external to the protective coating such as a jacket or plural coated optical fibres G02B6/44; coating of glass to obtain optical fibres C03C25/104
• CPC Class Codes: G02B 6/0281 Graded index region forming part of the central core segment, e.g. alpha profile, triangular, trapezoidal core G02B6/0288, G02B6/0286 take precedence
• CPC Class Codes: G02B 6/0365 arranged - - +
• CPC Class Codes: G02B 6/4411 Matrix structure
• CPC Class Codes: G02B 6/4429 Means specially adapted for strengthening or protecting the cables
• CPC Class Codes: G02B 6/4431 with provision in the protective covering, e.g. weak line, for gaining access to one or more fibres, e.g. for branching or tapping break-out terminations G02B6/4471
• CPC Class Codes: G02B 6/4432 with fibre reinforcements

Abstract

Fiber optic cables and methods of manufacturing fiber optic cables are disclosed herein. According to one embodiment, a fiber optic cable includes a plurality of optical fibers having a lay length of greater than 160 mm. The fiber optic cable also includes strength material surrounding the plurality of optical fibers and a polymer jacket surrounding the strength material. Each of the optical fibers is configured to exhibit a bend-induced optical attenuation of less than or equal to about 0.6 dB when wrapped one turn around a 7.5 mm mandrel.

Claims

1. A fiber optic cable comprising:

a plurality of optical fibers, wherein any lay length of the optical fibers is greater than or equal to about 1000 mm;

strength material surrounding the plurality of optical fibers, wherein any lay length of the strength material is greater than or equal to about 1000 mm; and

a polymer jacket surrounding the strength material;

wherein each of the optical fibers is configured to exhibit a bend-induced optical attenuation of less than 0.5 dB when wrapped one turn around a 10 mm diameter mandrel at an 850 nm wavelength.

2. The fiber optic cable of claim 1, wherein the strength material comprises strength members that are substantially parallel to one another.

3. The fiber optic cable of claim 1, wherein the strength material is stranded around the plurality of optical fibers.

4. The fiber optic cable of claim 1, wherein the plurality of optical fibers are substantially parallel to one another.

5. The fiber optic cable of claim 1, wherein the plurality of optical fibers is stranded.

6. The fiber optic cable of claim 1, wherein each of the optical fibers is configured to exhibit a bend-induced optical attenuation of less than 0.2 dB when wrapped one turn around a 10 mm diameter mandrel at an 850 nm wavelength.

7. The fiber optic cable of claim 1, wherein each of the optical fibers is a configured to exhibit a bend-induced optical attenuation of no more than 0.1 dB when wrapped one turn around a 10 mm diameter mandrel at all wavelengths between 800 nm and 1400 nm.

8. The fiber optic cable of claim 1, wherein each of the optical fibers is tight buffered optical fiber.

9. The fiber optic cable of claim 1, wherein the strength material comprises aramid fibers.

10. A fiber optic cable comprising:

a plurality of tight buffered optical fibers having a lay length of greater than 1000 mm, wherein each optical fiber comprises a core and a cladding that surrounds and is directly adjacent to the core, wherein the cladding of each optical fiber is surrounded by at least one coating, wherein the coating includes a low-modulus primary coating and a high-modulus secondary coating, wherein the coating is surrounded by the tight buffer, and wherein the tight buffer of each optical fiber is a substantially-cylindrical, outer extrusion of polymeric material that extends substantially coaxially around and is fixedly connected to the corresponding optical fiber;

strength material surrounding the plurality of tight buffered optical fibers; and

a polymer jacket surrounding the strength material;

wherein each of the tight buffered optical fibers is configured to exhibit a bend-induced optical attenuation of less than 0.5 dB when wrapped one turn around a 10 mm diameter mandrel at an 850 nm wavelength.

11. The fiber optic cable of claim 10, wherein the plurality of tight buffered optical fibers are substantially parallel to one another.

12. The fiber optic cable of claim 10, wherein each of the tight buffered optical fibers is configured to exhibit a bend-induced optical attenuation of less than 0.2 dB when wrapped one turn around a 10 mm diameter mandrel at an 850 nm wavelength.

13. The fiber optic cable of claim 10, wherein each of the tight buffered optical fibers is configured to exhibit a bend-induced optical attenuation of no more than 0.1 dB when wrapped one turn around a 10 mm diameter mandrel at all wavelengths between 800 nm and 1400 nm.

14. The fiber optic cable of claim 10, wherein the strength material comprises strength members that are substantially parallel to one another.

15. The fiber optic cable of claim 10, wherein the strength material has a lay length greater than or equal to about 500 mm.

16. The fiber optic cable of claim 10, wherein the strength material has a lay length greater than or equal to about 1000 mm.

17. The fiber optic cable of claim 16, wherein the strength material comprises aramid fibers.

18. The fiber optic cable of claim 10, wherein each of the tight buffered optical fibers exhibits an intrinsic optical attenuation of less than or equal to about 3.0 dB/km.

19. The fiber optic cable of claim 10, wherein there are at least 24 of the tight buffered optical fibers in the fiber optic cable.

20. The fiber optic cable of claim 10, wherein the polymeric material of the tight buffer is polyvinyl chloride.

21. The fiber optic cable of claim 10, wherein the optical fibers are stranded together with a lay length that approaches infinity.

22. A fiber optic cable comprising:

a plurality of tight buffered optical fibers having a lay length of greater than 1000 mm, wherein the tight buffer of each optical fiber is a substantially-cylindrical, outer extrusion of polymeric material that extends substantially coaxially around and is fixedly connected to the corresponding optical fiber, wherein;

a first group of the tight buffered optical fibers resides within an inner layer and a second group of the tight buffered optical fibers resides within an outer layer; and

the first group is immediately adjacent to the second group;

strength material surrounding the plurality of tight buffered optical fibers; and

a polymer jacket surrounding the strength material;

wherein each of the tight buffered optical fibers is configured to exhibit a bend-induced optical attenuation of less than 0.5 dB when wrapped one turn around a 10 mm diameter mandrel at an 850 nm wavelength.

23. The fiber optic cable of claim 22, wherein when flattened, the optical fibers of the inner and outer layers intermingle to minimize crushing forces and attenuation.

24. The fiber optic cable of claim 22, wherein the inner layer comprises three inner optical fibers and the outer layer comprises nine outer optical fibers.

25. The fiber optic cable of claim 22, wherein strength material is not positioned between the inner and outer layers of optical fibers, whereby when the cable is bent, the optical fibers there are easily displaced to form a flattened configuration at the bend.

26. The fiber optic cable of claim 22, wherein the outer layer of the optical fibers is positioned immediately adjacent to and surrounding the inner layer of optical fibers, thereby helping to reduce the diameter of the cable.