Abstract

We present measurements of narrowband amplification and energy extraction in a 60-J x-ray preionized electric-discharge XeCl laser. The seed radiation was obtained from a multistage oscillator–amplifier with a bandwidth that could be varied from ~80 MHz to >10 GHz. It was coupled into the laser amplifier resonator through a 2-in. diam hole in the rear mirror and made three passes in the amplifier before being coupled out. The amplifier resonator had no on-axis feedback and therefore acted as a three-pass amplifier. Its output spectrum and spatial mode were controlled by the properties of the input radiation rather than by the properties of the resonator itself. We present measurements of extraction efficiency for input wavelengths on and between the main gain lines of the XeCl laser and identify any effects of spectral pulling or broadening in the amplified radiation, as well as any effects related to delocking late in the pulse. We also investigate the extraction efficiency as a function of the energy and duration of the input pulse. These are the first measurements of this type to be obtained with an electric discharge excimer laser of this size. They are compared with results obtained on smaller excimer lasers, e-beam pumped lasers, and systems that use different amplifier resonator configurations.

© 1986 Optical Society of America