A transport model for a transverse electron beam-pumped semiconductor laser has been developed. The model incorporates spatial dependencies of the power deposition from the beam as well as a three-dimensional model of the gain medium and the field intensity of the photons produced by stimulated emission in the oscillation cavity. This model accounts for spatial inhomogeneities and has been solved for a variety of pumping strengths. The model was developed so that it can be benchmarked with electron beam pumping. The dominant mechanisms for the production of electron–hole pair production within the semiconductor material is similar to the dominant mechanisms for the production of electron–hole production using ion beams. Thus, the model can be extended to fission fragment ion pumping of semiconductor lasers in order to model a nuclear-pumped laser/reactor system.