High-pulse-repetition-rate HF laser with plate electrodes

Abstract

A high-pulse-repetition-rate electric-discharge HF laser with inductive—capacitive discharge stabilisation in the active H2—SF6—He mixture is studied. The multisectional discharge gap with a total length of 250 mm is formed by pairs of anode—cathode plates arranged in a zigzag pattern. The width of the discharge gap between each pair of plates is ∼1 mm and its height is ∼12 mm. The laser-beam cross section at the output cavity mirror is ∼9 mm × 11 mm. The maximum laser pulse energy and the maximum laser efficiency for the H2—SF6 mixture are 14.3 mJ and 2.1%, respectively. The addition of He to the mixture reduced the laser pulse energy by 10%—15%. The maximum gas velocity in the gap between the electrodes achieves 20 m s-1. The limiting pulse repetition rate flim for which a decrease in the laser pulse energy is still not observed is ∼2kHz for the H2—SF6 mixture and ∼2.4kHz for the H2—SF6—He mixture. The average output power ∼27 W is obtained for a pulse repetition rate of 2.4 kHz.