Development of a 2-kW XeCl laser with a surface coronapreionization scheme and a spiker-sustainer circuit

A maximum average power of 2.1 kW is demonstrated in a XeCl laser with an efficiency of 3.0% at a repetition rate of about 800 Hz. The 2-kW laser has a discharge region of 4 cm in gap length, 2.5 cm in discharge width, and an effective discharge length of 3 m with a resonator length of 5.2 m. A reverse voltage mode spiker-sustainer circuit makes it possible to apply a steep voltage rise of nearly 1000 kV/μs across the main discharge electrodes and to supply excitation energy effectively into the discharge region. The control of the preionization timing before the initiation of the spiker circuit is found to be indispensable in maintaining a homogeneous volume discharge under high repetition-rate operation. These techniques enable the laser to realize a long pulse excitation under the high repetition-rate operation conditions. The excitation process is analyzed by computer-model simulation. The application of a cascaded stable resonator has improved the average power by 6% compared with that of a conventional stable resonator