The paper presents the analysis of the experimental results obtained when investigating the HBr addition effect on the CuBr vapor laser generation power. It is shown that the positive effect of HBr addition is of a threshold nature: the increase of generation power occurs only after the excess of a definite level of the power introduced in a discharge. We considered the physical reasons of the generation power decrease in the presence of HBr addition at laser operation in the "reduced" energy contribution mode. The paper presents the results of the investigation of the threshold behavior depending on the addition concentration. It is shown that there exists the optimal HBr concentration when the laser operation efficiency is maximal.
laser, copper bromide, bromine hydrogen