Generation of polygonal non-diffracting beams via angular spectral phases

In this study, an effective approach for generating polygonal non-diffracting beams (PNDBs) is demonstrated using optical caustics and cross-phases. The resulting structured light beams display a polygonal transverse structure and exhibit a significant intensity gradient and phase gradient. Diverse PNDBs can be generated by flexibly controlling the exponent factor of the cross-phases. The experimental results show that this beam has excellent non-diffracting properties and could stably capture and manipulate particles to move along polygonal trajectories. Furthermore, by adjusting the conversion rate parameter of the cross-phase, PNDBs can manipulate the motion state of the trapped particles, such as start and stop. These various PNDBs may be useful for potential applications as optical tweezers and in micromachining.