Effect of longitudinal variations in current injection and carrier concentration in laser diodes

The effects of nonuniform current injection along the length of a semiconductor laser are investigated using multiple segmented stripe contact lasers. The results of the experiments are analyzed with a model for which the carrier concentration, gain, and photon density are functions of position. From the model, it was determined that nonuniform current injection caused large variations in the optical field within the laser, and the field produced a redistribution of electrical carriers in the active region. The nonlinearities in the light versus current measurements were explained by the redistribution of carriers as the optical field changed.