  We predict that the transverse electric-magnetic polarization splitting of
exciton-polaritons allows a simple technique for the generation of polariton
vortices of winding number 2 in semiconductor microcavities. The vortices can
be excited by circularly polarized light having no orbital angular momentum and
observed as phase vortices in the opposite circular polarization or directly as
linear polarization vortices. The prediction is explained by a simplified
analytical linear model and shown fully with a numerical model based on the
Gross-Pitaevskii equations, which includes the non-linear effects of
polariton-polariton interactions.
