Low loss single mode fiber with chlorine doped core

Abstract

An optical fiber comprising: (i) a chlorine doped silica based core comprising a core alpha (α)>10, and maximum refractive index delta Δ1max % and Cl concentration >1 wt %; (ii) a cladding surrounding the core, the cladding comprising: (a) an inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ2 and a minimum refractive index delta Δ2min such that Δ2min<Δ1max, the inner cladding region comprising fluorine doped silica and the refractive index delta Δ2 with region that decreases with radial position, and (b) an outer cladding region surrounding the inner cladding region and having refractive index delta Δ3, such that Δ2min<Δ3. The fiber has mode field diameter MFD at 1310 nm of ≥9 microns, a cable cutoff of ≤1260 nm, zero dispersion wavelength of 1300 nm≤zero dispersion wavelength ≤1324 nm and bend loss at 1550 nm for a 20 mm mandrel of less than 0.5 dB/turn.

Dependencies are inferred from the claim text.