  We demonstrate a polarization rotator based on optically confined
exciton-polariton condensate in elliptically shaped trap through nonresonant
excitation methods. This is made possible through the cavity inherent TE-TM
splitting which, due to the trap geometric ellipticity, breaks the ground state
spin-degeneracy. The emerging fine structure low- and high-energy modes are
shown to be polarized linear parallel and perpendicular to the trap major axis
respectively. We demonstrate stable polariton condensation into the excited
mode with high degree of linear polarization which rotates as we rotate the
trap. Our findings thus demonstrate a new type of optically tunable
polarization rotators with exciting perspectives for spinoptronic applications.
