Patent ID: 7835609
Filing Date: 2010-11-16
Classification: G02B

Abstract:
1. An optical fiber having a refractive index profile constituted by: a three-layer structured core which includes, in the central portion of the core, a first core having a substantially uniform positive relative refractive index difference Δ a cladding which surrounds and comes in contact with the three-layer structured core and has a substantially uniform refractive index, wherein Δ Δ when Δ Δ a cable cutoff wavelength is less than 1260 nm, a mode field diameter is in the range of 7.9 to 10.2 μm at a wavelength of 1.31 μm, a zero-dispersion wavelength is in the range of 1300 to 1324 nm, a zero-dispersion slope is equal to or less than 0.093 ps/(nm a uniform bending loss is equal to or less than 2 dB/m at a diameter of 20 mm and a wavelength of 1.31 μm, and an SBS threshold at a wavelength of 1.55 μm is higher than that of a single-mode optical fiber having a typical step-index profile and the same mode field diameter by +3 dB or higher.