Experimental observation of perturbation-induced intermittency in the dynamics of a loss-modulated CO2 laser

We show experimentally in the dynamics of a periodically perturbed CO2 laser with modulated losses that a different type of intermittency (the ''breathing effect'') [Z. Qu, G. Hu, G. Yang, and G. Qin, Phys. Rev. Lett. 74, 1736 (1995)], which is characterized by a regular alternation between periodic and chaotic behaviors, can be created by different methods. In addition to the usual way, (i) by suppressing chaos by weak perturbations, we have produced the breathing effect (ii) by destabilizing periodic stable orbits created at a period-doubling bifurcation and (iii) by means of large amplitude perturbations in the bistability domain between coexisting attractors. In addition, we also observed the crisis of a strange attractor induced by periodic perturbations and phase effects in the nonfeedback control of laser dynamics.