Engineered polarization control of GaAs/AlGaAs surface-emitting lasers by anisotropic stress from elliptical etched substrate hole

The engineered polarization control of surface emitting (SE) lasers, based on the observed evidence of the polarization determination, is reported. 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. The polarization control has been demonstrated with about 80% reproducibility in etched-well-type surface emitting (SE) lasers by employing a thick gold film or a polyimide as a stress-enhancing material.>