Off-axis amplification of picosecond UV pulses by an electric-discharge XeCl excimer laser with a beam divergence close to the diffraction limit

This paper describes experiments involving the off-axis amplification of picosecond UV pulses by an XeCl electric-discharge excimer laser. It is shown that the increase in beam divergence due to this amplification is insignificant. The observed divergence of an axially symmetric beam with a diameter of 45 mm exceeds the diffraction limit by only a factor of 1.3 (for a pulse energy of 50 mJ).