ENGINEERED POLARIZATION CONTROL OF GAAS/ALGAAS SURFACE-EMITTING LASERS BY ANISOTROPIC STRESS FROM ELLIPTIC ETCHED SUBSTRATE HOLE

We have performed an engineered polarization control of surface emitting (SE) lasers based on the observed evidence of the polarization determination. Thermally stressed epitaxial layers including an active region are made anisotropic by an elliptically etched substrate structure. This stress causes an anisotropy in optical gain of the active region. We have demonstrated the polarization control with about 80% reproducibility in etched-well-type SE lasers by employing a thick gold film or a polyimide as a stress-enhancing material.