Increase of the mode size in a laser with a stimulated Brillouin scattering mirror

An experimental investigation was made of the factors leading to an increase in the mode size in a laser with an ‘external’ stimulated Brillouin scattering mirror. An increase in the wings of the transverse distribution of the laser beam, inaccurate phase conjugation, and broadband pumping tended to increase the mode size and the output radiation energy.