Eur. Phys. J. Special Topics 223, 1729-1742 (2014)
https://doi.org/10.1140/epjst/e2014-02124-0

Regular Article

Spatiotemporal polarization dynamics in a transverse multimode CO₂ laser with optical feedback

¹ Istituto Nazionale di Ottica-CNR, Firenze, Italy
² Department of Physics, College of Science, University of Baghdad, Baghdad, Iraq
³ CNR-SPIN Complesso Universitario di M.S. Angelo, Napoli, Italy
⁴ INFN Sez .di Napoli, Napoli, Italy
⁵ High Institute of Telecommunications and Post, Al Salihiya, Baghdad, Iraq
⁶ Università di Firenze, Italy

Received: 26 February 2014
Revised: 26 February 2014
Published online: 19 March 2014

Abstract

We investigate the polarization dynamics in a quasi-isotropic CO₂ 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 dynamics is well reproduced by a model that discriminates between the intrinsic asymmetry due to the kinetic coupling of molecules with different angular momenta and the anisotropy induced by the polarization feedback. We observe various dynamical regimes including chaotic dynamics and show that feedback changes these states from regular to chaotic and vice versa. Finally, the possible applications to polarization coding are discussed.