Unstable Resonator Magnification Effects in a Short-pulse XeCl Laser

Abstract

The output characteristics of a short-pulse discharge-pumped XeCl laser have been examined as a function of the instability of the associated optical resonator. Using a continuously-coupled resonator configuration, the beam divergence, pulse energy and duration are systematically reduced as the roundtrip magnification factor is increased from M = 3 to M = 63. Furthermore, the laser output is shown to depend not simply on the value of M but, in a more complicated way, on the particular single-pass magnifications M ₁₂ and M ₂₁ in the cavity. This is attributed to the shortness of the inversion lifetime in the laser.