Performance of axicon based conical resonator (ABCR) with a xenon chloride (XeCl) excimer laser

New cavity configuration namely the axicon based conical resonator (ABCR) was demonstrated in a XeCl excimer laser for achieving high misalignment tolerance, low beam divergence and high pointing stability. Using this resonator configuration misalignment tolerance of about ~10 mrad was achieved, which was ~20 times higher than ~0.25-0.5 mrad normally achieved with conventional plane-plane cavity in case of excimer lasers, which is significant improvement and the beam divergence was also reduced considerably to ~0.8 mrad simultaneously. Shot to shot pointing stability was established using this novel configuration by recording SEM (scanning electron microscope) images of clean micro-holes without heat affected zone, which otherwise is extremely difficult to achieve in excimer lasers. SEM images show large improvement in focusing properties and pointing stability using conical resonator as compared to standard plane-plane cavity normally used in excimer lasers.