Low bend loss coated optical fiber

• US 7,539,381 B2
• Filed: 05/11/2007
• Issued: 05/26/2009
• Est. Priority Date: 05/11/2007
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Li, Ming-Jun, Chen, Xin, Wang, Jianguo, Koh, Joohyun, Liu, Anping
• Primary Examiner(s): Font; Frank G
• Assistant Examiner(s): Mooney; Michael P
• Application Number:
  US11/801,896
• Publication Number:
  US 20080279516A1
• Time in Patent Office: 746 Days
• Field of Search: 385123-124, 385126-128, 385/141, 385144-145
• US Class Current: 385/124
• CPC Class Codes: C03C 25/106 Single coatings
• 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 6/03683 arranged - - + +

Abstract

An optical fiber includes a core and a cladding, said cladding having a refractive index n_c a first coating directly contacting the cladding of said fiber, said coating having a thickness of less than 10 microns, said coating having a refractive index delta %=100×(n_i²−n_c²)/2n_i² less than −1 percent. In another aspect, an optical fiber includes a core and a cladding, said cladding having a refractive index n_c, a first coating directly contacting the cladding of said fiber, said fiber comprising a glass diameter less than 100 microns, said coating having a thickness of at least 8 microns, said coating having a refractive index delta %=100×(n_i²−n_c²)/2n_i² less than −1 percent.

Claims

1. A glass optical fiber comprising a core and a cladding, said cladding having a refractive index n_c a first coating directly contacting the cladding of said fiber, said coating having a thickness of less than 10 microns, said coating having a refractive index delta %=100×

(n_i²−

n_c²)/2n_i² less than −

1 percent.

2. The optical fiber of claim 1, wherein said first coating comprises a thickness of less than 7 microns.

3. The optical fiber of claim 1, wherein said first coating comprises a thickness of less than 5 microns.

4. The optical fiber of claim 1, wherein said coating comprises a terploymer containing N-halogenated phenyl maleimide unit or N-halogenated phenyl bismaleimide unit, one or more second units selected from the group consisting of halogenated acrylates, halogenated styrenes, halogenated vinyl ethers, halogenated olefins, halogenated vinyl isocyanates, halogenated N-vinyl amides, halogenated allyls, halogenated propenyl ethers, halogenated methacrylates, halogenated maleates, halogenated itaconates, and halogenated crotonates and one or more third units comprising a monomer containing both a free radically polymerizable group and cationic ring opening polymerizable group.

5. The optical fiber of claim 4, wherein said terploymer is prepared by radical co-polymerization prior to being applied to the fiber.

6. The optical fiber of claim 1, further comprising a second coating surrounding said first coating and having a Young'"'"'s modulus less than about 200 MPa.

7. The optical fiber of claim 6, wherein said fiber further comprises a third coating surrounding said second coating, and having a Young'"'"'s modulus of greater than about 600 MPa.

8. The optical fiber of claim 1, whereins said fiber exhibits a 20 mm bend induced loss of less than 0.12 dB/turn at 1550 nm.

9. The optical fiber of claim 1, wherein the core is single moded at at least one wavelength selected from the group consisting of 850, 1060, 1310, and 1550 nm.

10. The optical fiber of claim 1, wherein said fiber has an outer glass cladding diameter of less than 100 microns.

11. The optical fiber of claim 1, wherein said fiber has an outer glass cladding diameter of less than 90 microns.

12. An optical fiber comprising a core and a cladding, said cladding having a refractive index n_c a first coating directly contacting the cladding of said fiber, said fiber comprising a glass diameter less than 100 microns, said coating having a thickness of at least 8 microns, said coating having a refractive index delta %=100×

(n_i²−

n_c²)/2n_i² less than −

1 percent.

13. The optical fiber of claim 12, wherein said fiber exhibits a glass diameter less than 90 microns.

14. The optical fiber of claim 12, wherein said coating exhibits thickness of at least 20 microns.

15. The optical fiber of claim 12, wherein said coating comprises a terploymer containing N-halogenated phenyl maleimide unit or N-halogenated phenyl bismaleimide unit, one or more second units selected from the group consisting of halogenated acrylates, halogenated styrenes, halogenated vinyl ethers, halogenated olefins, halogenated vinyl isocyanates, halogenated N-vinyl amides, halogenated allyls, halogenated propenyl ethers, halogenated methacrylates, halogenated maleates, halogenated itaconates, and halogenated crotonates and one or more third units comprising a monomer containing both a free radically polymerizable group and cationic ring opening polymerizable group.

16. The optical fiber of claim 15, wherein said terploymer is prepared by radical co-polymerization prior to being applied to the fiber.

17. The optical fiber of claim 12, further comprising a second coating surrounding said first coating and having a Young'"'"'s modulus less than about 200 MPa.

18. The optical fiber of claim 12, wherein said fiber further comprises a third coating surrounding said second coating, and having a Young'"'"'s modulus of greater than about 600 MPa.

19. The optical fiber of claim 12, wherein the core is single moded at at least one or more wavelengths selected from the group consisting of 850, 1060, 1310, and 1550 nm.

20. The optical fiber of claim 12, wherein said fiber exhibits a 20 mm bend induced loss of less than 0.12 dB/turn at 1550 nm.