Optimization of the index profile of an optical fiber at N wavelengths

The paper provides simple expressions for the dopant concentrations that optimize the bandwidth of a fiber at a number of wavelengths. The solution is related to Olshansky's multiple alpha profiles. Numerical application is made for germania, fluor, and phosphorus doping at wavelengths where the losses are small. The effect of a free parameter on the fiber Delta and its bandwidth is outlined.