Low bend loss optical fiber with a chlorine doped core and offset trench

Abstract

An optical fiber includes (i) a chlorine doped silica based core having a core alpha (Coreα)≥4, a radius r1, and a maximum refractive index delta Δ1 max% and (ii) a cladding surrounding the core. The cladding surrounding the core includes a) a first inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ2, a radius r2, and a minimum refractive index delta Δ2 min such that Δ2 min<Δ1 max, b) a second inner cladding adjacent to and in contact with the first inner cladding having a refractive index Δ3, a radius r3, and a minimum refractive index delta Δ3 min such that Δ3 min<Δ2, and c) an outer cladding region surrounding the second inner cladding region and having a refractive index Δ5, a radius rmax, and a minimum refractive index delta Δ3 min such that Δ3 min<Δ2. The optical fiber has a mode field diameter MFD at 1310 of ≥9 microns, a cable cutoff of ≤1260 nm, a zero dispersion wavelength of 1300 nm≤zero dispersion wavelength ≤1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel of less than 0.75 dB/turn.

Dependencies are inferred from the claim text.