Polarization Behavior and Mode Structure of Elliptical Surface Relief VCSELs

We report on experimental studies of the polarization behavior and mode structure of the linearly polarized light emitted by transverse surface relief Vertical-Cavity Surface-Emitting Lasers. The latter were constructed such as to enhance the single mode operation by introducing spatially distributed losses and to enhance polarization stability by making these losses anisotropic. Investigating the influence of the orientation of the surface relief with respect to the [100] crystallographic axis shows that the polarization direction is governed by the orientation of the index ellipsoid, whereas the selection of the lasing mode is mainly determined by the anisotropy in the losses introduced by the surface relief. I