Synchronization conditions for one mo del of an optical laser Anatoly M. Samoilenko Institute of Mathematics NAS, Kiev, Ukraine e-mail: sam@imath.kiev.ua By using methods of perturbation theory, we investigate the global behavior of tra jectories on a toroidal attractor and in its neighborhood for a system of differential equations that appears in the study of the synchronization of oscillations of the mathematical model of an optical laser.