This repository contains the numerical data and results from an investigation into the design of multi-step-index (MSI) multimode fibers. The study focuses on fibers featuring a cladding trench designed to support 55 spatial modes at a wavelength of 1550nm, utilizing a highly efficient, gradient-based radial fiber mode solver.Contents:Modal Dispersion Analysis: We provide the modal dispersion profiles for an MSI fiber with a 25.5µm radius. The dataset includes both the initial designs and the final optimised profiles for comparative analysis.Comparative Benchmarking: The complete results are illustrated in dmd_results_oecc.png, which features an optimised parabolic fiber profile as a performance benchmark.Refractive Index Profiles: The repository includes the specific fiber refractive index profiles corresponding to the modal dispersion data generated by the gradient-based solver.Optimisation Progress: Loss function plots are provided to demonstrate the evolution of the design, specifically showing the reduction of maximum modal dispersion throughout the optimisation process.