Development of compact UV lasers with pulse repetition rate up to 5 kHz

Abstract

Investigation results of high-frequency XeF, KrF and N₂ lasers with an electrode unit, based on multisectional discharge gap with an inductive-capacitive discharge stabilization, are presented in the paper. The main direction of the research was obtaining the highest pulse repetition rates with their high stability. The pulse repetition rates up to 4...5 kHz were realized in UV lasers at relatively low gas flow velocity (16...19 m/s). The relative root-mean-square (rms) deviation of the laser pulse energy (&sigma;) in the XeF laser was &sigma; = 2.3% at <i>f</i> = 5 kHz, in the KrF laser &sigma; = 3.2% at <i>f</i> = 4.5 kHz, in the nitrogen laser &sigma; = 1.6% at <i>f</i> = 4.5 kHz. Influence of different factors on the stability of the pulses energy of the laser radiation was studied. It is shown that existence of inductive-capacitive decoupling between cathode plates in the KrF (XeF) and N₂ lasers made it possible to increase the limiting frequency for the KrF (XeF)-laser on 1...2 kHz keeping the same &sigma;. The best stability of the laser pulses energy was obtained at location of the preionizer sparks upwards on the gas flow. In the nitrogen laser we recorded periodical change of the &sigma; value.