The present invention embraces a multimode optical fiber that includes a central core having an alpha-index profile, an inner cladding, a depressed trench, and an outer cladding (e.g., an outer optical cladding). Typically, the central core's alpha-index profile has a minimum refractive index at the central core's radius that corresponds to a refractive index difference with respect to the outer cladding. The optical fiber achieves reduced bending losses and a high bandwidth with a reduced cladding effect for high-data-rate applications.