We experimentally study the polarization dynamics of a single-mode CO<sub>2</sub> laser during the switch-on transient of the laser intensity. We find a strong competition between two linearly polarized fields, which finally collapse into a single field. As a result of this competition, the two coexisting fields oscillate out of phase by π rad for time intervals much longer than that of the relaxation oscillation. One can control the oscillation frequency of the two polarized fields by varying the intracavity anisotropies. This phenomenon is interpreted in the framework of Maxwell–Bloch equations by addition of nonlinear terms to the polarization equations that allow the fields to compete while they interact with the same population inversion.
© 2001 Optical Society of America
(140.0140) Lasers and laser optics : Lasers and laser optics
(260.5430) Physical optics : Polarization
(270.2500) Quantum optics : Fluctuations, relaxations, and noise
(270.3430) Quantum optics : Laser theory
I. Leyva, E. Allaria, and R. Meucci, "Polarization competition in a quasi-isotropic CO2 laser," Opt. Lett. 26, 605-607 (2001)