Spatial and Temporal Dependence of the Gain of a Transversely Excited Pulsed CO2 Laser

The gain of a transversely excited pulsed CO2 laser with distributed electrodes has been examined with and without the addition of hydrogen. Spatially, the gain shows a sharp peak a few millimeters from the cathode, followed by a region of relatively uniform gain. The gain of the latter region increases from 13 to 18 dB/m upon the addition of hydrogen. The gain-vs-time curves show peaks which propagate from cathode to anode at velocities ranging from 600 to 1200 m/sec.