Competition effects in the polarization of light in a quasi-isotropic laser

We report on two experiments involving polarization competition in a quasi-isotropic 3.39-μm He–Ne laser. In one, competition between externally determined polarization modes yields a crenellated line shape, except for small frequency ranges where residual anisotropies become important. In the second experiment, the internal anisotropies are determined and controlled by a tilted internal talon. Here, dips and peaks are observed in the intensity output of the laser.