Patent ID: 6965719

Claim:
A dispersion compensating optical fiber comprising: an uncovered dispersion compensating optical fiber containing a core and a cladding; a resin coating which is disposed around the uncovered dispersion compensating optical fiber and which has an adhesive property of 10 g/mm or less, the adhesive property being defined by variation range of tension in an optical fiber when the optical fiber is unwound from a wound state; 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 resin coating, wherein an outer diameter of the uncovered dispersion compensating optical fiber is in a range from 90 to 125 μm, and an outer diameter of the dispersion compensating optical fiber is in a range from 180 to 250 μm, wherein the dispersion compensating optical fiber has an effective area of 19 μm 2 or more, a wavelength dispersion of −70 ps/nm/km or less, and a cut-off wavelength which is capable of substantially single mode propagation, in an employed wavelength band selected from the range of 1.52 to 1.63 μm, and the compensation ratio of the dispersion slope is 80 to 120% when the wavelength dispersion of a single mode optical fiber having a zero dispersion wavelength shorter than the employed wavelength band is compensated for by using the dispersion compensating optical fiber having a length enough to compensate for the wavelength dispersion of the single mode optical fiber to zero or nearly zero, and wherein the uncovered dispersion compensating optical fiber has a refractive index profile including a center core portion; a core portion provided around the outer periphery of the center core portion and having a lower refractive index than that of the center core portion; a ring core portion provided around the outer periphery of the core portion and having a lower refractive index than that of the center core portion and a higher