Origin of chaotic relaxation oscillations in an optically pumped molecular laser

We show that pump-induced modifications to the gain and dispersion profiles can induce a weak side-band modulation which acts as a driving term to sustain chaotic relaxation oscillations in a single-mode, resonant, optically pumped molecular laser. Our study suggests that a careful two- or more-parameter unfolding of higher-codimension bifurcations should lead to a wealth of nonlinear dynamical behavior within easy access of current experiments.