LASER-BEAM QUALITY OF HIGH PULSE REPETITION FREQUENCY EXCIMER LASERS

The influence of acoustic perturbations of an active disturbing medium on the far-field diffraction pattern is both theoretically and experi mentally investigated. The theoretical results are in good agreement w ith experiments performed with a high repetition rate excimer laser (l ambda=308 nm, PRF=500 Hz). This theoretical approach explains the decr ease of laser energy and fluence and the distortion of the beam shape in the far-field occurring in high pulse repetition frequency excimer lasers.