Flat-top beams are a light beam with a relatively flat intensity profile -- in contrast to Gaussian beams, for example. They often have a super-Gaussian shape.
flat-top beams, explained by RP; top-hat beam, supergaussian, intensity profile, beam shaper
Understand the difference between Tophat beam and Gaussian beam in one article
Top Hat Beam Shaper, Square Top Hat Spot
Gauss to Top-Hat beam shaping with a, TopShape
PA-15 de Mata Et Al, PDF, Laser
Process Overview DEGRADATION AND SURFACE ENGINEERING
Flat Top Laser Beam - Holo Or
Flat Top Beam Shaper - New Span Opto-Technology Inc
Flat-top laser beams: Their uses and benefits
PoloRevBucketSP S/M BEAMS
flat-top beams, explained by RP; top-hat beam, supergaussian, intensity profile, beam shaper
Laser intensity profile based terahertz field enhancement from a mixture of nano-particles embedded in a gas
Why Use a Flat Top Laser Beam?
Top-Hat / Flat-Top Beam Shaper application notes - Holo Or