Control of vertical-cavity laser polarization with anisotropic transverse cavity geometries

Abstract
We show the two-fold polarization degeneracy of etched air-post vertical-cavity surface emitting laser diodes can be lifted and a dominant polarization state selected through use of anisotropic transverse laser cavity geometries. For lasers with rhombus-shaped cavities, fundamental mode lasing emission linearly polarized along one specified crystal axis is obtained up to twice the threshold current. For dumbbell-shaped lasers, fundamental mode lasing emission linearly polarized along one specified crystal axis is maintained over the entire operating range of the device producing a maximum orthogonal polarization suppression ratio of 14 dB.