<title>Influence of fabrication precision on laser beam forming by fabricated optics</title>

Abstract

The profile of a laser beam was transformed into a rectangular uniform profile using a fabricated mirror. However, intensity ripples in the lransformed beam were observed. These intensity ripples resulted from small ripples on the fabricated mirror surface. The peak-to-valley height and the peak-to-peak distance of the ripples on the mirror surface due to the fabrication error are 1.2 mm and about 10 nm, respectively. We evaluated the effect of these small ripples on the transformed intensity profile by calculating the laser beam propagation characteristics. The calculated laser beam profile was similar to the actual beam profile, and exhibited intensity ripples. Therefore, the intensity ripples of the reshaped beam resulted from the small ripples on the fabricated surface with the peak-to-valley height of 1/60 A . These ripples on the fabricated surface were probably caused by the feed speed error of the x-y stage of the fabrication machine.