Abstract

Recently, coupled stripe diode laser arrays have received much attention because of their potential in producing single-mode high-power radiation. These structures generally exhibit multiple far-field lobes with low gain differences between lateral modes. We report the investigation of the modes of broad stripes with various gain profiles. For our numerical model, a multiple layer staircase approximation is used for the complex refractive-index profile and we use an iterative approach based on successive approximations to the complex propagation constant to determine the modes of the structure. A mode stability criterion based on the gain difference between the (symmetric) fundamental mode and higher-order modes is developed. Intramodal gain difference is also determined for coupled-stripe arrays and unstable resonators with curved mirrors. Conclusions regarding the suitability of each of these structures for high-power single-mode operation are presented.

© 1986 Optical Society of America