POLARIZATION SWITCHING IN AN ANISOTROPIC CAVITY COHERENTLY PUMPED J=1-]J'=0 LASER

We show that, in an optically pumped resonant J = 1 --> J' = 0 laser, a grain anisotropy is induced by a linearly polarized coherent pump be am that can be balanced or countered by x-y cavity-loss anisotropies, leading to switching between the x and y linearly polarized states of the generated laser field as the laser intensity is increased. This sw itching is not brought about by selection of the mode with the maximum emission intensity. A domain of bistability between the two Linearly polarized states is found, whose width depends on the value of the dec ay rate of the two photon coherence induced among the sublevels of the J = 1 level manifold. Differently from the incoherently pumped J = 1 --> J' = 0 laser, the decay rate for the magnetic dipole in that manif old has no influence on the polarization of the emission.