Properties of a laser with an unstable resonator containing small-scale phase inhomogeneities

Results are presented of numerical calculations of the dominant mode field distribution for an unstable resonator filled with an active medium and containing small-scale inhomogeneities. Results are also presented of experiments using these resonators in a cw CO₂ laser. The results of investigations show that the existence of small-scale phase inhomogeneities on the resonator axis may sharply increase the laser radiation density inside the resonator and substantially decrease the axial brightness of the beam.