Ianus, the three-electrode excimer laser

We present the results of the mechanical, electrical, and optical characterisation work done on Ianus, a 1 : 1 laser-head prototype of the XeCl (lambda = 308 nm) laser (1-kW output power) developed in the frame of the Eureka EU 213 program. The three-electrode configuration of Ianus consists of two laser discharges electrically in series, with the same current flowing through the two gaps, but geometrically in parallel. We have experimentally tested and optimised the behaviour of this unconventional laser head with regard to single-shot laser output energy, overall efficiency and spatial discharge uniformity, as well as to repetition-rate performance versus a newly defined volumetric flush factor. The peculiar three-electrode concept makes Ianus suitable for spiker-sustainer excitation and compact oscillator-amplifier configurations.