Fig. 7.5, Scheme of the laser processing with different spatially shaped beams (fluence profile and corresponding ablation topography). Gaussian laser beam (a), top hat laser beam (b) - Optically Induced Nanostructures - NCBI Bookshelf
Flat-Top Converter | Top Hat – Workshop of Photonics
Top-Hat / Flat-Top Beam Shaper application notes - Holo Or