Injection Locking of a Modified-Unstable-Resonator XeCl Laser by Using a Line-Narrowed Hemiconfocal Oscillator

Abstract

An injection-locked XeCl excimer laser with a modified positive-branch confocal unstable resonator was developed and the output characteristics were investigated. We utilized the hemiconfocal scheme in the line-narrowed oscillator in order to obtain a seed beam with high energy as well as narrow linewidth. In this case we obtained 0.05 cm-1 linewidth with 10 µ J output energy. The maximum output energy of the injection-locked oscillator was 110 mJ, which is 15% greater than that with free-running oscillation. We also presented a new method which can simply measure the power gain of the amplifier, by which the small signal gain coefficient of the amplifier was measured to be 10%/cm.