Micromodule Cables and Breakout Cables Therefor

• US 20100209059A1
• Filed: 02/15/2010
• Published: 08/19/2010
• Est. Priority Date: 02/16/2009
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: CCS Technology Inc. (Corning Incorporated)
• Inventors: Hurley, William C., Smith, David H., Conrad, Craig M.
• Granted Patent: US 8,582,941 B2
• Time in Patent Office: Days
• US Class Current: 385/110
• CPC Class Codes: G02B 6/0288 Multimode fibre, e.g. graded index core for compensating modal dispersion
• CPC Class Codes: G02B 6/0365 arranged - - +
• CPC Class Codes: G02B 6/4401 Optical cables glass fibres with a protective coating G02B6/02395
• 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
• CPC Class Codes: G02B 6/4477 with means for strain-relieving to interior strengths element

Abstract

Micromodule breakout cables are constructed to pass selected burn tests while maintaining a desired degree of accessibility and durability. The micromodule cables can be incorporated in data centers and are robust enough to serve as furcation legs while allowing hand accessibility. The cables can incorporate optical fibers with low delta attenuation and can have low skew.

Claims

1. A breakout cable, comprising:

a polymer jacket; and

a plurality of micromodules enclosed within the jacket, each micromodule having a plurality of optical waveguides and a polymer sheath comprising PVC surrounding the waveguides, the polymer sheath having a thickness in the range of 0.2 mm to 0.3 mm.

2. The breakout cable of claim 1, wherein the cable satisfies the NFPA 262 plenum burn test.

3. The breakout cable of claims 2, wherein the PVC is a highly-filled PVC.

4. The breakout cable of claim 3, wherein when the cable is subjected to a corner bend load of eight kilograms, delta attenuation at 850 nm in the cable due to the load is less than 0.3 dB.

5. The breakout cable of claim 3, wherein when the cable is subjected to a corner bend tie down test at two tie down bend locations of 25.4 mm radius, delta attenuation at 850 nm in the cable due to the bend is less than 0.05 dB.

6. The breakout cable of claim 3, wherein the at least one optical waveguide in the micromodules can be accessed by tearing the micromodule sheath with a user'"'"'s fingers.

7. The breakout cable of claim 3, wherein the skew for a micromodule is less than 3.75 ps/m.

8. The breakout cable of claim 3, wherein the at least one optical waveguide comprises a plurality of multimode optical fibers.

9. The breakout cable of claim 3, further comprising an aramid strain-relief element adjacent to an interior of the polymer jacket.

10. The breakout cable of claim 3, wherein when subjected to a corner bend load of six kilograms, delta attenuation at 850 nm in the cable due to the load is less than 0.4 dB.

11. The breakout cable of claim 1, wherein the at least one optical waveguide in the micromodules can be accessed by tearing the micromodule sheath with a user'"'"'s fingers.

12. The breakout cable of claim 1, further comprising an aramid strain-relief element adjacent to an interior of the polymer jacket.

13. A micromodule cable, comprising:

an outer jacket;

a plurality of breakout units enclosed in the outer jacket, each breakout unit having a plurality of micromodules and a jacket enclosing the micromodules, and each micromodule having at least one optical waveguide and a polymer sheath surrounding the at least one optical waveguide and having a thickness in the range of 0.2 mm to 0.3 mm; and

a central strength member, the breakout units being arranged around the central strength member.

14. The micromodule cable of claim 13, wherein the micromodule cable satisfies the NFPA 262 plenum burn test.

15. The micromodule cable of claim 14, wherein the at least one optical waveguide in the micromodules can be accessed by tearing the micromodule sheath with a user'"'"'s fingers.

16. The micromodule cable of claim 14, further comprising a strain-relief element adjacent to an interior of the breakout unit jackets.

17. The micromodule cable of claim 14, wherein the central strength member comprises glass-reinforced plastic.

18. A micromodule cable, comprising:

an outer jacket;

a plurality of breakout units enclosed in the outer jacket, each breakout unit having a plurality of micromodules, a jacket enclosing the micromodules, and an aramid strain relief element adjacent to the jacket, with each micromodule having at least one optical waveguide and a polymer sheath surrounding the at least one optical waveguide and having a thickness in the range of 0.1 mm to 0.3 mm; and

a central strength member, the breakout units being arranged around the central strength member, wherein

the micromodule cable satisfies the NFPA 262 plenum burn test,

each polymer sheath comprises PVC, and

the at least one optical waveguide in the micromodules can be accessed by tearing the micromodule sheath with a user'"'"'s fingers.

19. A data information transfer system, comprising:

a plurality of servers, each server having a plurality of optical ports; and

at least one micromodule cable comprising an outer jacket;

a central strength member; and

a plurality of breakout cables enclosed in the outer jacket, each breakout cable comprising a plurality of micromodules, at least one micromodule of the breakout cables being connected to at least one of the optical ports, wherein

each micromodule comprises a plurality of optical waveguides and a polymer sheath comprising PVC surrounding the waveguides, the polymer sheath having a thickness in the range of 0.2 mm to 0.3 mm

20. The data information transfer system of claim 19, wherein the at least one optical waveguide includes a plurality of multimode optical fibers and the micromodule cable complies with NFPA 262.

21. A method of calculating jacket thickness for a cable, the method comprising:

calculating a maximum jacket thickness for a selected material using the formula;

Material_Modulus=590(Wall_thickness)^1.2, wherein

Material_Modulus is the modulus for the material and Wall_thickness is the jacket thickness.