Symmetry breaking and bifurcations in lasers

The breaking of the axial symmetry may alter significantly the bifurcation structure of a laser, at least in some regimes. It is therefore important to develop a coherent and rigorous approach to model generic symmetry breaking in laser models in order to compare their predictions with experimental results. This study presents an approach to this problem by deriving the normal form equations for a two level laser in the presence of symmetry breaking. The authors pose restrictions neither on the type of symmetry that is broken nor on the mechanism that lifts the degeneracy and obtain a set of ordinary differential equations whose coefficients can be put in direct relationship to experimentally accessible parameters.