Patent ID: 7773846

Claim:
An optical fiber for transmitting optical signals comprised of light, the optical fiber comprising: a core region disposed about a longitudinal centerline and having a refractive index profile with a first refractive index, and a cladding region surrounding the core region, the cladding region comprising at least one annular region having an index of refraction lower than that of the remainder of the cladding; 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 31 (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 wherein the optical fiber has a fiber cutoff of less than 1400 nm.