Crush-resistant fiber optic cables employing bend-resistant multimode fibers
A crush-resistant fiber optic cable is disclosed, wherein the cable includes a plurality of bend-resistant multimode optical fibers. The fibers are generally arranged longitudinally about a central axis, with no strength member arranged along the central axis. A tensile-strength layer surrounds the plurality of bend-resistant optical fibers. A protective cover surrounds the tensile-strength layer and has an outside diameter D O in the range 3 mm≦D O ≦5 mm.
1. A crush-resistant fiber optic cable having a central axis, comprising:
a plurality of bend-resistant multimode optical fibers generally arranged longitudinally about the central axis, with no strength member arranged along the central axis;
a tensile-strength layer surrounding the plurality of bend-resistant optical fibers; and
a protective cover surrounding the tensile-strength layer and having an outside diameter D O in the range 3 mm≦D O ≦5 mm, wherein the protective cover has a thickness T 50 in the range 0.75 mm≦T 50 ≦1.25 mm.
2. The crush-resistant fiber optic cable of claim 1 , wherein the tensile-strength layer comprises aramid yarn.
3. The crush-resistant fiber optic cable of claim 1 , wherein each bend-resistant multimode optical fiber has a nominal diameter of about 250 microns.
4. The crush-resistant fiber optic cable of claim 1 , wherein the plurality of bend-resistant multimode optical fibers comprises at least twelve optical fibers.
5. A crush-resistant fiber optic cable having a central axis, comprising:
a plurality of bend-resistant multimode optical fibers generally arranged longitudinally about the central axis, with no strength member arranged along the central axis;
a tensile-strength layer surrounding the plurality of bend-resistant optical fibers; and
a protective cover surrounding the tensile-strength layer and having an outside diameter D O in the range 3 mm≦D O ≦5 mm,
wherein under a crush load of 100N/cm for 10 minutes, the optical fibers exhibit a delta attenuation of less than 0.4 decibels at a wavelength of 850 nanometers.
6. The crush-resistant fiber optic cable of claim 1 , wherein under a crush load of 100N/cm for 10 minutes, the optical fibers exhibit a delta attenuation of less than 0.3 decibels at a wavelength of 850 nanometers.
7. The crush-resistant fiber optic cable of claim 1 , wherein under a crush load of 100N/cm for 10 minutes, the optical fibers exhibit a delta attenuation of less than 0.8 decibels at a wavelength of 1300 nanometers.
8. The crush-resistant fiber optic cable of claim 1 , wherein under a crush load of 100N/cm for 10 minutes, the optical fibers exhibit a delta attenuation of less than 0.4 decibels at a wavelength of 1300 nanometers.
9. The crush-resistant fiber optic cable of claim 4 , wherein the tensile-strength layer comprises aramid yarn, each bend-resistant multimode optical fiber has a nominal diameter of about 250 microns.
10. The crush-resistant fiber optic cable of claim 1 , wherein the plurality of bend-resistant multimode optical fibers each have a nominal diameter of about 250 microns;
wherein the layer of aramid yarn is immediately surrounding the plurality of bend-resistant optical fibers; and
wherein the protective cover is immediately surrounding the tensile-strength layer.
11. The crush-resistant fiber optic cable of claim 10 , wherein the plurality of bend-resistant multimode optical fibers comprises at least twelve optical fibers.
12. The crush-resistant fiber optic cable of claim 10 , wherein under a crush load of 100N/cm for 10 minutes, the optical fibers exhibit a delta attenuation of less than 0.4 decibels at a wavelength of 850 nanometers.
13. The crush-resistant fiber optic cable of claim 10 , wherein under a crush load of 100N/cm for 10 minutes, the optical fibers exhibit a delta attenuation of less than 0.3 decibels at a wavelength of 850 nanometers.
14. The crush-resistant fiber optic cable of claim 10 , wherein under a crush load of 100N/cm for 10 minutes, the optical fibers exhibit a delta attenuation of less than 0.8 decibels at a wavelength of 1300 nanometers.
15. The crush-resistant fiber optic cable of claim 10 , wherein under a crush load of 100N/cm for 10 minutes, the optical fibers exhibit a delta attenuation of less than 0.4 decibels at a wavelength of 1300 nanometers.
16. The crush-resistant fiber optic cable of claim 10 , wherein the protective cover comprises PVC, the plurality of bend-resistant multimode optical fibers comprises at least twelve optical fibers, and the outside diameter D O is less than 4.5 mm.
17. A method of forming a crush-resistant fiber optic cable having a central axis, comprising:
disposing a plurality of bend-resistant multimode optical fibers generally longitudinally about the central axis, with no strength member arranged along the central axis;
surrounding the plurality of bend-resistant optical fibers with a tensile-strength layer;
extruding a protective cover around the tensile-strength layer, the protective cover having an outside diameter D O in the range 3 mm≦D O ≦5 mm; and
forming the tensile-strength layer from wound aramid yarn, wherein the plurality of bend-resistant multimode optical fibers comprises at least twelve optical fibers
wherein the protective cover comprises PVC and has a thickness T 50 in the range 0.75 mm≦T 50 ≦1.25 mm.
18. The crush-resistant fiber optic cable of claim 5 , wherein the tensile-strength layer comprises aramid yarn.
19. The crush-resistant fiber optic cable of claim 5 , wherein each bend-resistant multimode optical fiber has a nominal diameter of about 250 microns.
20. The crush-resistant fiber optic cable of claim 5 , wherein the plurality of bend-resistant multimode optical fibers comprises at least twelve optical fibers.