Spatiotemporal dynamics of lasers in the presence of an imperfect O(2) symmetry.

We show theoretically and experimentally that an infinitesimal imperfection in the symmetry of a system has a macroscopic influence on the stability of spatiotemporal patterns originated in a symmetry breaking process. This result makes it possible to discuss differences between experiments and models in which such corrections have not been taken into account. We show that the stability of the solutions arising from the first symmetry breaking transition in the Maxwell-Bloch equations is valid for every laser with radial symmetry.