1. The problem statement, all variables and given/known data A multimode step index fiber has a relative index difference of 1% and a core refractive index of 1.5. The number of modes propagating at a wavelength of 1.3μm is 1100. Estimate the diameter of the fiber core. An optical link of 6 km uses the above fiber. Find (a) the delay difference between the slowest and fastest modes at the fiber output (b) the rms pulse broadening due to intermodal dispersion on the link (c) the maximum bit rate may be obtained without substantial errors on the link assuming only intermodal dispersion (d) the bandwidth‐ length product 2. Relevant equations 3. The attempt at a solution i am not sure how to start, this course is a open source course and no textbook is provided so i am really stucked with how to even estimate the diameter.