Patent ID: 6731847
Filing Date: 2004-05-04
Classification: G02B

Abstract:
An optical fiber comprising:a core extending along a predetermined axis; an inner cladding which is a region provided on the outer periphery of said core and has a lower refractive index than said core; and an outer cladding which is a region provided on the outer periphery of said inner cladding and has a refractive index lower than that of said core but higher than that of said inner cladding; wherein the relative refractive index difference of said core with respect to said outer cladding is 0.30% or more but 0.50% or less, the relative refractive index difference of said inner cladding with respect to said outer cladding is âˆ’0.50% or more but âˆ’0.02% or less, the dispersion at a wavelength of 1.55 &mgr;m is greater than 18 ps/nm/km and, and an effective area at the wavelength of 1.55 &mgr;m is 70 &mgr;m2 or more.