On the extension of the pulse length of a discharge excited ArF excimer laser

The present study concerns the generation of long laser pulses of a dischar ge pumped ArF excimer laser (193 nm). The laser performance depends strongl y on the discharge stability. The spatial homogeneity of the preionization and the partial press;re of the fluorine in the laser gas mixture are criti cal. The best results are obtained by using a spiker-sustainer excitation s cheme having a fast voltage polarity reversal in the electron multiplicatio n phase of the discharge. We were able to obtain pulse lengths of up to 120 ns.