Patent ID: 6952519

Claim:
An optical fiber comprising: a length; a core having a refractive index profile and a centerline, the core comprising a central region having a maximum relative refractive index Δ 1MAX , an intermidiate region surrounding and directly adjacent the central region, the intermediate region having a minimum relative refractive index Δ 2MIN , and an outer region surrounding and directly adjacent the intermediate region, the outer region having a maximum relative refractive index Δ 3MAX , wherein Δ 1MAX >Δ 2MIN and Δ 3MAX >Δ 2MIN ; and a cladding layer surrounding and directly adjacent the core; wherein the optical fiber has an attenuation at 1550 nm; wherein the refractive index of the core is selected to provide: an absolute SBS threshold in dBm greater than about 9.3+10log[(1−e −(0.19)(50)/4.343 )/(1−e −(α)(L)/4.343 )], wherein L is the length in km and α is the attenuation in dB/km at 1550 nm.