Polarization spatial dynamics in a transverse multimode CO2 laser with optical feedback

We experimentally study the polarization dynamics in a quasi isotropic CO
₂
laser emitting on the TEM
^*
₀₁
mode subjected to an optical feedback. We observe a complex dynamics in which spatial mode and polarization competition are involved. The observed dynamic is well reproduced by means of a model that provides a quantitative discrimination between the intrinsic asymmetry due to the kinetic coupling of molecules with different angular momenta and the anisotropy induced by the polarization feedback. Possible applications to polarization coding and synchronization will be presented.