Patent ID: 7496261
Filing Date: 2009-02-24
Classification: G02B

Abstract:
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/nm