An optical attachment of an excimer laser beam that enables the transformation and optimization of spatial characteristics of a coherent UV beam was studied in an experimental setting. Experiments revealed that a rectangular 3 × 20 mm laser beam with the a divergence of 2 × 5 mrad attains a square shape of 20 × 20 mm and a divergence of 5 × 5 mrad in orthogonal directions after passing through the beam attachment. It is demonstrated that the application of a beam attachment in installations for material microprocessing simplifies optical layout of the illumination module allows one to obtain optimal homogeneity of sample illumination (under 2%) upon the projection of the image on the processing plane of the sample with submicron precision and to reduce the radiation load on optical elements via the elimination of hot spots.
Gavrilov, E. V., Zhevlakov, A. P., Kascheev, S. V., Kujanpää, V., & Savinainen, T. (2011). Transformation of spatial characteristics of excimer laser radiation. Optics and Spectroscopy, 110(1), 145-149. https://doi.org/10.1134/S0030400X11010048