Generation of high uniformity flat-top beams by reconstructing the amplitude distribution at descending edges

A methodology for generation of high uniformity flat-top beams by reconstructing target beam amplitude distribution (RTAD) at descending edge is proposed. To achieve flat-top beams with high uniformity, the novel amplitude distribution serves as an alternative for geometrical patterns in iterative algorithms. The descending edge elegantly bridges the discontinuities between the flat-top region and the background, effectively mitigating the occurrence of spectral leakage. The RTAD methodology performs remarkable uniformity of 98.8% coupled with energy efficiency of 76.3% in numerical simulations and the flat-top beam uniformity can maintain at 91.0% in experiments, outperforming the conventional algorithms. A series of geometric flat-top beams are obtained by RTAD methodology, such as rectangle, triangle, pentagon and hexagon, etc. These results highlight the tremendous potential of RTAD methodology in the fields of flat-top beam shaping and laser processing.