Patent ID: 7340141

Claim:
A single mode optical fiber for enabling wavelength division multiflexing transmission at a wavelength range of 1,460 to 1,625 nm, the optical fiber having a transmission rate of 10 Gb/s and a channel spacing of 50 GHz or less, and comprising: (a) a core region positioned in an optically central axis and having a radius (r 1 ) from the optically central axis and a specific refractive index difference (Δ 1 ); and (b) a clad region surrounding the core region and having a radius (r 2 ) from the optically central axis and a specific refractive index difference (Δ 2 ); the optical fiber also having: (c) a stepped refractive index profile where each radius of the regions is r 1 <r 2 , and the specific refractive index difference is Δ 1 >Δ 2 , and Δ 1 >0; (wherein, Δ 1 (%)=[(n core −n clad )/n clad ]×100, n core : a refractive index of the core region, n clad : a refractive index of the clad region) wherein, (d) a dispersion value of at least 9 ps/nm-km at 1,460 nm; (e) an effective sectional area of 45 μm 2 ˜65 μm 2 at 1,460 nm; and (f) a zero-dispersion wavelength existing at 1,370 nm or less, and a positive dispersion slope.