Breaking spatial periodicity: aperiodic combined microlens array for suppressing interference lattices in beam homogenization

Periodic microlens arrays (MLAs) produce interference lattices when homogenizing highly coherent beams. We propose an aperiodic combined microlens array (CMLA) comprising seamlessly tiled multiscale sub-lenses with a constant F-number and 100% fill factor. Aperiodic displacements and aperture diversity disrupt phase matching and redistribute interference energy in the spatial-frequency domain. Experiments show a rectangular flat-top beam with a uniformity of 86.2%, modulation depth of 0.220, and spectral disorder index of 0.844, outperforming periodic MLAs. The CMLA offers a compact, passive route to coherent-beam homogenization.