Measurements of intrinsic efficiency and parameters of an electron beam pumped ArXe laser

Measurements of the output energy and intrinsic efficiency of an electron beam pumped ArXe laser operating on the 1.73 μm line are reported. A 220 kV electron beam was used to pump either an 11 x 11 x 50 cm3 or an 11 x 11 x 25 cm3 active volume. Small-signal gain, nonsaturable loss, and saturation flux were deduced via a Rigrod analysis of the output energies as a function of output coupler reflectivity. Electron beam pump powers ranging from 2.2 to 16.2 kW/cm3 were employed. At a pump power of 2.2 kW/cm3 a small signal of 0.035 cm-1, a gain to loss ratio of 272, and a saturation flux of 2.1 kW/cm2 were determined. Intrinsic efficiencies of 4 percent were obtained at the lower pump powers. From the measurements of the laser output it is clear that the secondary electrons have a significant impact on the laser kinetics and efficiency