Multimode optical fibers

A multimode optical fiber comprising:

• a core portion comprising an α-profile, a core maximum relative refractive index ΔCmax at or proximate a centerline of the core portion, and a core minimum relative refractive index ΔCmin at an outer radius of the core portion, wherein ΔCmax is less than or equal to 0.85 Δ% and greater than or equal to −0.1 Δ%, ΔCmax>ΔCmin, and ΔCmin is less than 0 Δ%;
• a depressed index trench portion circumferentially surrounding the core portion, the depressed index trench portion comprising a minimum relative refractive index ΔTmin;
• a shelf portion circumferentially surrounding and directly contacting the depressed index trench portion, the shelf portion comprising a maximum relative refractive index ΔSmax;
• and
• an outer cladding portion circumferentially surrounding and directly contacting the shelf portion, the outer cladding portion comprising a relative refractive index ΔOC, wherein:
• Δ
• Cmin
• >
• Δ
• Tmin
• ;
• Δ
• Cmax
• ≥
• Δ
• Smax
• ;
• Δ
• Smax
• >
• Δ
• Tmin
• ;
• Δ
• Smax
• >
• Δ
• OC
• ;
• each of the core portion, the depressed index trench portion, and the outer cladding portion comprise silica-based glass down-doped with fluorine;
• and
• the multimode optical fiber is multimoded at wavelengths up to 1600 nm.