NONLINEAR DYNAMICS OF LASER SYSTEMS WITH A DELAY

A review is given Of the work done on nonlinear dynamics of laser syst ems with a delaying feedback loop when the transit time along this loo p is comparable with or greater than the time constants representing t he changes in the main characteristics of a system. An analysis is mad e of the delay in a feedback loop responsible for the lasing process i tself, and also in an external feedback loop which controls one of the laser parameters. Differential-difference equations describing the la sing dynamics are formulated. The evolution of the dynamics because of a change in the delay time is studied. The mechanisms and the conditi ons of formation of periodic pulses with different structures are dete rmined. Asymptotic characteristics (profile, amplitude, and period) of regular regimes and the dependences of their characteristics on the d elay are found. The phenomenon of multistability is demonstrated. It i s shown that a hysteresis of the period, amplitude, and structure of p ulses may be observed. The ways by which transitions of the dynamics t o chaos take place are identified.