In some implementations, a device may generate a data set including at least modal gain values and modal loss values for a semiconductor optical amplifier (SOA) slice. The device may determine, based on the data set, respective widths for a plurality of slices of an SOA using an autoregressive model. A width, of the respective widths, for a slice, of the plurality of slices, may be associated with a maximum conversion efficiency achievable for the slice at a given current density. The device may generate information indicating a geometry for the SOA based on the respective widths for the plurality of slices.