LASER PARAMETER CONTROL: Oscillation spectra of Ar-Xe and He-Ar-Xe mixtures pumpbed by a radially converging electron beam with a pulse length ~ 0.1 ms
We have investigated lasers oscillating on atomic transitions of xenon and pumped by a radially converging electron beam with pulse lengths between 0.07 and 0.1 ms. We have determined experimentally the dependence of the threshold beam current density and the output spectrum on the Q-factor of the laser resonator. We have shown that for beam current densities smaller than 16 mA/cm2 and for a pulse length ~ 0.1 ms there is a quasisteady lasing at wavelengths λ = 1.73, 2.65, 2.03, and 2.63 μm if the resonator output mirror and the mixture composition are chosen appropriately. We have also observed simulatenous oscillation on the following pairs of lines: λ = 1.73 and 2.03 μm, 2.03 and 2.65 μm, and 2.65 and 2.63 μm. When the lattice supporting the foil covering the beam window was cooled with water, periodic-pulse operation at a repetition rate of 5 Hz was achieved in a laser with a pumped volume ~ 18 liters.