| US 7,496,261 B2 | ||
| Dispersion compensating optical fiber and dispersion compensating optical fiber module | ||
| Kazuhiko Aikawa, Sakura (Japan); Yutaka Nagasawa, Sakura (Japan); Shogo Shimizu, Sakura (Japan); Takaaki Suzuki, Sakura (Japan); Masakazu Nakayama, Sakura (Japan); Kuniharu Himeno, Sakura (Japan); Ryozo Yamauchi, Sakura (Japan); Keiji Ohashi, Sakura (Japan); and Munehisa Fujimaki, Sakura (Japan) | ||
| Assigned to Fujikura Ltd., Tokyo (Japan) | ||
| Filed on Aug. 15, 2005, as Appl. No. 11/203,890. | ||
| Application 11/203890 is a continuation in part of application No. 10/104916, filed on Mar. 21, 2002, granted, now 6,965,719. | ||
| Claims priority of application No. P2001-193556 (JP), filed on Jun. 26, 2001. | ||
| Prior Publication US 2006/0062534 A1, Mar. 23, 2006 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. G02B 6/036 (2006.01) | ||
| U.S. Cl. 385—127 | 17 Claims |
| 1. A dispersion compensating optical fiber comprising:
an uncovered dispersion compensating optical fiber;
a double-layered resin coating disposed around the uncovered dispersion compensating optical fiber; and
an outer coating layer having a thickness of 3 to 7 μm, containing silicone in an amount of 1 to 5% by weight, and disposed
around the double-layered resin coating,
wherein the outer diameter of the uncovered dispersion compensating optical fiber is in a range from 90 to 125 μm, an outer
diameter of the dispersion compensating optical fiber is in a range from 180 to 250 μm,
wherein the uncovered dispersion compensating optical fiber comprises:
a cladding;
a central core region having a higher refractive index than that of the cladding;
a depressed core region which is located around the central core region, and which has a lower refractive index than that
of the cladding; and
a ring core region which is located around the depressed core region and inside the cladding, and which has a higher refractive
index than that of the cladding,
wherein the radius of the ring core region is set in a range from 6.5 μm to 9.5 μm, the radius ratio of the depressed core
region relative to the central core region is set in a range from 2.0 to 4.0, and the radius ratio of the ring core region
relative to the depressed core region is set in a range from 1.1 to 2.0,
wherein the relative refractive index difference of the central core region relative to the cladding is set in a range from
+1.00% to +1.90%, the relative refractive index difference of the depressed core region relative to the cladding is set in
a range from −0.60% to −1.00%, and the relative refractive index difference of the ring core region relative to the cladding
is set in a range from +0.20% to +1.00%, and
wherein at at least one wavelength selected from the range from 1.53 μm to 1.63 μm, chromatic dispersion of the dispersion
compensating fiber is in a range from −50 ps/nm/km to −150 ps/nm/km, the dispersion slope is in a range from −0.25 ps/nm2/km to −3.0 ps/nm2/km, the ratio of the dispersion slope relative to the chromatic dispersion is in a range from 0.005 nm−1 to 0.020 nm−1, and the dispersion compensating fiber has a cut-off wavelength which substantially enables single mode transmission.
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