EFFETS DE COMPETITION DANS LA POLARISATION DE LA LUMIÈRE D'UN LASER QUASI-ISOTROPE

Light polarization in a quasi-isotropic laser is very sensitive to small anisotropies wich break the axial cylindrical symmetry. These anisotropies are either internal or induced by light fedback inside the laser by the detector for example1. Moreveover they vary in general with frequency. The result is that light polarization can vary with frequency in the emission line : the laser eigenvectors become frequency-dependent. Moreover polarization flips between eigenvectors are induced by competition effects. We give here examples illustrating both phenomena. One application is the polarization flip interferometry2