Narrow-linewidth gain and saturation measurements of a KrF discharge laser

The gain and output characteristic of a KrF discharge laser module have been studied using a 0.1-cm−1 linewidth probe pulse generated from an etalon-narrowed injection-locked oscillator-amplifier system. A small signal gain coefficient of 0.115 cm−1 was measured. Saturation of the output intensity could be accurately modelled by assuming steady state conditions including a nonsaturable absorption of 0.01 cm−1 which yields a saturation intensity of 1.7 MW/cm2.