Dynamics of stimulated emission from a multimode laser considered allowing for stimulated Brillouin scattering

A multimode laser with a dynamic system typical of intracavity laser spectroscopy is analyzed allowing for a mechanism that may possibly flatten the stimulated emission spectrum when stimulated Brillouin scattering (STBS) occurs in the active medium. A numerical analysis of the dynamics of such a laser is carried out in terms of kinetic equations. It is found that STBS in an active medium shifts the lasing spectrum with time in the direction of the red wavelengths. The time needed for the establishment of dips in the emission spectrum of a laser, corresponding to narrow-band absorption lines, decreases on increase in the nonlinearity, but the relative depth of the dips decreases. An effect similar to the condensation of the spectrum in the vicinity of an absorption line is predicted.