Effect of buffer gas pressure on the spatiotemporal evolution of small-signal gain in copper vapor laser

We report the effect of buffer gas neon pressure on the spatiotemporal small signal gain evolution characteristics of a copper vapor laser CVL. The CVL discharge tube of diameter 47 mm and length 150 cm is studied for neon pressure from 20 to 70 mbar. The gain evolution is mapped by a specially generated 6-ns, 510.6-nm probe pulse. The evolution of gain at the center and at the edge are found to be widely different for different gas pressures. At lower pressure 20 mbar, the gain at the edge is higher compared to that at the center, however, the situation is reversed at higher pressure 70 mbar. The increased laser-circuit impedance matching and the reduced discharge plasma skin effect with increase in buffer gas pressure are the possible mecha- nisms responsible for such a changeover. © 2006 Society of Photo-Optical In