Comparison of beam quality parameters of two high peak power excimer laser beams

A comparison is made between the beam quality parameter M-2 and a new times-diffraction-limit-factor (TDL) for two high peak power XeCl lasers. The laser systems, equipped with unstable resonators, emit beams with different geometrical characteristic and optical quality. The results show that the M-2-factor is always larger than the TDL value and this discrepancy increases if the beam is almost diffraction-limited. A novel method to obtain the far-field profile of coherent supergaussian-like beams and a simple technique to estimate the beam angular stability of a pulsed laser are also presented.