ACOUSTIC-WAVE ORIGIN IN EXCIMER LASERS

This paper investigates the acoustic wave formation processes inside a n excimer laser system. Accurate discharge stability diagnostics achie ved with a fast CCD camera and a piezoelectric pressure probe show a s trong correlation between the electric arcs appearing during the disch arge and the acoustic waves created in excimer laser devices. This exp erimental result is confirmed by a simple three dimensional modelisati on describing the propagation of acoustic waves issued from the discha rge electric arcs in a passive closed volume. The classical laser work ing conditions and the non machine-dependent hypotheses relevant to th e modelisation allow to extend the conclusions of this study to mostly excimer laser devices. In particular, even though they have been obta ined under the single shot regime and without gas flow, the results ca n be applied to high PRF excimer laser systems.