Polarization dependent threshold of a polymer laser

Summary form only given. Almost all lasers emit light with a well-defined polarization. The direction of this polarization is determined by dichroic and birefringent properties of the complete laser, i.e. of both the cavity and the active medium. In optically pumped lasers one has access to the dichroism and/or birefringence of the gain medium through, for instance, the polarization of the optical pump beam. Light-emitting polymers in solution provide a case where the induced anisotropy decays very slowly. We show the temporal evolution of the spontaneous-emission radiation of a co-polymer of PPV derivatives.