Effect of inhomogeneities of an active medium on the divergence of radiation from a long-pulse electric-discharge XeCl laser

The effect of optical inhomogeneities of the active medium of an electric-d ischarge XeCl laser excited by 300-ns pulses on the divergence of amplified radiation is experimentally studied. The possibility of obtaining the diff raction-limited divergence of radiation at the output of the amplifier is s hown. Under our conditions, for the pump power density exceeding 400 kW cm( -3), the radiation divergence in mainly determined by the nonuniformity of the gain profile of the active medium that appears at a certain stage of th e discharge burning. This property of the active medium is caused by the de velopment of macro- and microinhomogeneities; of the discharge current.