Studies on high energy pulsed CO 2 laser

Abstract

The recent results on pulsed CO 2 laser, including the effects of preionization structure, electrode profile, and discharge circuit are reported. Two sizes of discharge gap, 70 mm and 100 mm were selected. For the 70 mm gap, lateral preionization was used; for the 100 mm gap, preionization beneath the meshed electrode, and mixed preionization beneath and beside the electrodes were all tested. Strong lateral discharge was found in the case of near-Rogowski profile or Stappaerts profile, and strong central discharge was found in the case of Ernst profile. When the nearRogowski profiled electrode was paired with an Ernst profiled electrode, better performance was obtained. Discharge distribution corresponding to the spark pins under the mesh grid was found obviously, which means that the uniformity of preionization should be further improved. Small signal gain coefficient was measured to evaluate the discharge. For the experimental setup with 70 mm discharge gap and 4 liters discharge volume, the highest small signal gain coefficient was 2.94% cm -1 . When a laser cavity was installed, the highest pulsed energy obtained from this setup was 169 J. When the discharge volume was enlarged to 16 liters, pulsed laser energy up to 580 J was obtained.