PARABOLIC-CONFOCAL UNSTABLE-RESONATOR SEMICONDUCTOR-LASERS - MODELINGAND EXPERIMENTS

Surface-emitting all-grating-based resonator lasers, suitable for inte gration with diffractive beam-forming elements, have been experimental ly theoretically studied. The lasers exhibit single spatial mode opera tion for a device width of 160 mu m. The device performance is modeled using a beam propagation method, which accounts for spatial hole burn ing as well as thermal and carrier diffusion effects. Near- and far-fi eld calculations are incorporated to facilitate the comparison with th e experimental results, To achieve high-quality beam forming, it is es sential that wavefront of the guided optical mode is well defined stab le. Using the model, we study the dependence of the wavefront distorti on on various parameters and show how these distortions affect the far -field characteristics. The results from the simulations agree well wi th the experimental work. We find that the laser performance is to a l arge extent controlled by thermal effects. At low-power operation, the se effects can he compensated for, for a range of the injection curren t, by modifications of the resonator or outcoupler grating geometries.