Repetitively pulsed operation of an injection-controlled high-power XeF(C→A) excimer laser

The operation at a 1-Hz repetition frequency of an injection-controlled electron-beam-pumped XeF(C→A) excimer laser system is reported. A compact, halogen-compatible, closed flow loop incorporating a transverse inline fan was used for gas circulation. In single-laser-shot operation, the timing between an electron beam and the injection dye laser was carefully adjusted to obtain an optimum laser pulse energy stability. An improved output-laser energy of 1.2 J per pulse with an intrinsic efficiency of 1.1% at 486.8 nm was achieved with a large-aperture unstable resonator. Interferograms taken during and after an electron-beam pump pulse to determine the minimum optical cavity recovery time of this device indicate that stable laser output energy performance at repetition rates of up to 25 Hz could be achieved with the present flow loop