Bend Resistant Multimode Optical Fiber

• US 20090169163A1
• Filed: 10/14/2008
• Published: 07/02/2009
• Est. Priority Date: 12/13/2007
• Status: Abandoned Application

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Li, Ming-Jun, Bookbinder, Dana Craig, Bickham, Scott Robertson, Abbott, John Steele III
• Application Number:
  US12/250,987
• Publication Number:
  US 20090169163A1
• Time in Patent Office: Days
• US Class Current: 385/127
• CPC Class Codes: G02B 6/0288 Multimode fibre, e.g. graded index core for compensating modal dispersion
• CPC Class Codes: G02B 6/0365 arranged - - +

Abstract

Bend resistant multimode optical fibers are disclosed herein. Multimode optical fibers disclosed herein comprise a core region and a cladding region surrounding and directly adjacent to the core region, the cladding region comprising a depressed-index annular portion comprising a depressed relative refractive index which is spaced from the core at least 0.5 microns and less than 4 microns.

Claims

1. A multimode optical fiber comprising:

a graded index glass core; and

an inner cladding surrounding and in contact with the core, and a second cladding comprising a depressed-index annular portion surrounding the inner cladding, said depressed-index annular portion having a refractive index delta less than about −

0.2% and a width of at least 1 micron, wherein the width of said inner cladding is at least 0.5 microns and less than 4 microns.

2. The optical fiber of claim 1, wherein said inner cladding has a refractive index delta greater than −

0.05% and less than 0.05% and comprises an inner radius of about 25 microns and the width of said inner cladding is at least 1 micron.

3. The optical fiber of claim 1, wherein the width of said inner cladding is less than 3 microns.

4. The fiber of claim 1, wherein said fiber further exhibits a 1 turn 30 mm diameter mandrel wrap attenuation increase of less than or equal to 0.1 dB/turn at 850 nm.

5. The fiber of claim 1, wherein said fiber further exhibits a 1 turn 20 mm diameter mandrel wrap attenuation increase, of less than or equal to 0.1 dB/turn at 850 nm.

6. The fiber of claim 1, wherein said fiber further exhibits a 1 turn 10 mm diameter mandrel wrap attenuation increase, of less than or equal to 0.5 dB/turn at 850 nm.

7. The fiber of claim 2, wherein said depressed-index annular portion has a width greater than 2 microns.

8. The fiber of claim 7, wherein said depressed-index annular portion has a width less than 10 microns.

9. The fiber of claim 1, wherein said fiber further exhibits an overfilled bandwidth greater than 1.5 GHz-km at 850 nm.

10. The fiber of claim 1, wherein said fiber further exhibits an overfilled bandwidth greater than 2.0 GHz-km at 850 nm.

11. The fiber of claim 1, wherein said fiber further exhibits an overfilled bandwidth greater than 4.0 GHz-km at 850 nm.

12. The fiber of claim 1, wherein said fiber further exhibits an overfilled bandwidth greater than 500 MHz-km at 1300 nm.

13. The fiber of claim 1, wherein said depressed-index annular portion exhibits a refractive index delta less than −

0.3 percent.

14. The fiber of claim 1, wherein said depressed-index annular portion exhibits a refractive index delta less than −

0.4 percent.

15. The fiber of claim 1, wherein said depressed-index annular portion comprises fluorine doped silica.

16. The fiber of claim 1, wherein said depressed-index annular portion comprises a plurality of non-periodically disposed voids.

17. The fiber of claim 1 wherein the maximum refractive index delta of the graded index glass core is greater than 0.5% and less than 1.2%.

18. The fiber of claim 1 wherein the 1 turn 10 mm diameter attenuation increase is less than 0.6 dB for all wavelengths between 800 and 1400 nm.

23. The multimode fiber of claim 1 further comprising a numerical aperture of greater than 0.14.

19. A multimode optical fiber comprising:

a graded index glass core; and

an inner cladding surrounding and in contact with the core, and a second cladding comprising a depressed-index annular portion surrounding the inner cladding, said depressed-index annular portion having a refractive index delta less than about −

0.2% and a width of at least 1 micron, wherein the width of said inner cladding is at least 0.5 microns and said fiber further exhibits a 1 turn 10 mm diameter mandrel wrap attenuation increase, of less than or equal to 0.4 dB/turn at 850 nm, and an overfilled bandwidth greater than 1.5 GHz-km at 850 nm.

20. The multimode fiber of claim 19 further comprising a numerical aperture of greater than 0.18.

21. The multimode fiber of claim 19, wherein said depressed-index annular portion comprises fluorine.

22. The multimode fiber of claim 19, wherein said fiber further exhibits an overfilled bandwidth greater than 2.0 GHz-km at 850 nm.