A multimode optical fiber includes a central core having a graded-index profile with a delta value of about 1.9 percent or greater. The graded-index core profile has at least two different alpha parameter values along the core radius, namely a first value in an inner zone of the central core and a second value in an outer zone of the central core. The second alpha parameter value is typically less than the first alpha parameter value. The graded-index core profile and its first derivative are typically substantially continuous over the width of the graded-index core.
