Width of the active mode-locking zone in a solid-state laser

A theoretical analysis is made of the stability of active steady-state mode-locking in a neodymium-doped garnet laser with periodic loss modulation against two types of perturbation—small perturbations of the parameters of ultrashort pulses generated under steady-state conditions and excitation of additional ultrashort pulses on exposure to the spontaneous emission noise. It is shown that the growth of perturbations of the second type limits the width of the steady-state active mode-locking zone.