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

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 f_lim 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.