Influence of non-uniformity of active medium of a long-pulse electric discharge XeCl amplifier on radiation divergence

摘要

Influence of active medium non-uniformity of 300 ns pulse pump electric discharge XeCl laser on divergence of amplified radiation has been investigated. It was shown that in case of 100-200 kW/cm~3 pump power the laser active media allows to amplify the diffraction limited laser beam practically without distortion. In case of 400-500 kW/cm~3 pump power after 120 ns of discharge burning the micro- and macro-inhomogeneities appeared. These inhomogeneities increased the amplified radiation divergence. It was established that basic reason of a divergence degeneration was inhomogeneity of gain profile in active medium. In our case amplification increased when the macro-inhomogeneities developed and the absorption increased when the micro-inhomogeneities developed in local regions of active medium.