Prediction of Transverse-Mode Selection in Double Heterojunction Lasers by An Amipolar Excess Carrier Diffusion Solution

Transverse-mode selection is characterized for GaAs/AlGaAs double heterojunction lasers from optical field and elcetron/hole interaction. The electron/hole distribution determined from a solution of the ambipolar diffusion equation provides the necessary information about gain/mode coupling to predict the current at threshold. Lasing power out versus current solutions provide information about internal differential quantum efficiency. Theory is matched to experiment for a multimode laser with one heterojunction having a very small index step. It is found that the laser's characteristics over a temperature and current range are predicted by adjusting the active-layer refractive index as determined from far-field measurements. Published in the Journal of Applied Physics, v54 n2 p540-549, Feb 1983.