MANY-BODY EFFECTS ON OPTICAL GAIN IN STRAINED HEXAGONAL AND CUBIC GANAIGAN QUANTUM-WELL LASERS/

Theoretical results on the optical gain of strained hexagonal and cubi c GaN/AlGaN quantum well (QW) lasers taking into account of many-body effects are presented. These results are also compared with those of t he free-carrier theory without the many-body effects. The band structu re is calculated by using the Hamiltonian based on the Rashba-Sheka-Pi kus 6 x 6 Plamiltonian. It is found that the peak gain for cubic and h exagonal QW lasers is increased by about 45% and 37%, respectively, ne ar the transparency carrier density due to the Coulomb enhancement. Al so, the gain peaks with many-body effects are redshifted relative to t hose without many-body effects by similar to 130 meV at higher carrier densities. These results indicate the importance of the many-body eff ects for both cubic and hexagonal GaN/AlGaN QW lasers. (C) 1997 Americ an Institute of Physics.