A method of fabricating a multimode optical fiber including at least a core region, an inner cladding region and an outer cladding region, the method comprising the steps of: (a) determining desired performance characteristics, including effective mode bandwidth and/or differential modal delay, of the multimode optical fiber, (b) determining desired structural characteristics of the multimode optical fiber, (c) determining the numerical aperture and a bandwidth of the multimode optical fiber, (d) determining dopants that will be incorporated into the core region of the multimode optical fiber, (e) setting up a numerical optimization code to generate dopant concentration profiles of each of said dopants by reducing a variation of z(r, λ) with respect to wavelength, where z r λ ≜ n 2 r λ k 0 2, r is a core region radius, λ is a wavelength, n is the refractive index of the core region, and k 0 = 2 π / λ is the wave number, wherein the reducing step is a min-max operation as follows: max λ ∈ Λ z r λ − z cl λ e d − 1 ≤ ε p where Λ is the bandwidth, z cl ( λ) is z of said outer cladding region, e d = z ( r, λ d) - z cl ( λ d) and λ d is a design wavelength λ d ∈ Λ and ε p is an optimization tolerance parameter, and wherein, for the bandwidth Λ = [ λ L, λ U] having a lower wavelength bound λ L and an upper wavelength bound λ U, the concentrations and distributions of said dopants are radially varied within the transverse cross-section of said core region so that ε p, L = a 1 λ d − λ L + a 0; ε p, U = a 1 λ d − λ U + a 0 ε p = min ε p, L ε p, U where 0 ≤ a 1 ≤ 0.0025, 0 ≤ a 0 ≤ 0.05, (f) providing the dopant concentration profiles to a deposition system that produces a multimode optical fiber preform in which the concentration of each dopant in its core region corresponds to the inputted profiles, and (g) drawing the multimode optical fiber from the multimode optical fiber preform. (a) determining desired performance characteristics, including effective mode bandwidth and/or differential modal delay, of the multimode optical fiber, (b) determining desired structural characteristics of the multimode optical fiber, (c) determining the numerical aperture and a bandwidth of the multimode optical fiber, (d) determining dopants that will be incorporated into the core region of the multimode optical fiber, (e) setting up a numerical optimization code to generate dopant concentration profiles of each of said dopants by reducing a variation of z(r, λ) with respect to wavelength, where z r λ ≜ n 2 r λ k 0 2, r is a core region radius, λ is a wavelength, n is the refractive index of the core region, and k 0 = 2 π / λ is the wave number, wherein the reducing step is a min-max operation as follows: max λ ∈ Λ z r λ − z cl λ e d − 1 ≤ ε p where Λ is the bandwidth, z cl ( λ) is z of said outer cladding region, e d = z ( r, λ d) - z cl ( λ d) and λ d is a design wavelength λ d ∈ Λ and ε p is an optimization tolerance parameter, and wherein, for the bandwidth Λ = [ λ L, λ U] having a lower wavelength bound λ L and an upper wavelength bound λ U, the concentrations and distributions of said dopants are radially varied within the transverse cross-section of said core region so that ε p, L = a 1 λ d − λ L + a 0; ε p, U = a 1 λ d − λ U + a 0 ε p = min ε p, L ε p, U where 0 ≤ a 1 ≤ 0.0025, 0 ≤ a 0 ≤ 0.05, (f) providing the dopant concentration profiles to a deposition system that produces a multimode optical fiber preform in which the concentration of each dopant in its core region corresponds to the inputted profiles, and (g) drawing the multimode optical fiber from the multimode optical fiber preform.