Continuously adjustable hollow beam for ultrafast laser fabrication of size-controllable nanoparticles.

ABSTRACT: The focused vortex beam generates a hollow beam, which has been widely used for size-controlled nanoparticle formation on various materials. However, the size variation of the vortex beam is limited by the integral order of the 2π phase wrap, while the waste is caused by the large side lobe around the center. In this study, we propose a method for hollow beam generation by splitting a femtosecond laser and imparting opposite phases to the outer annular region and the central Gaussian region. After focusing, these two regions overlap at the focal spot, resulting in a hollow beam due to phase cancellation. By modulating the relative dimensions of these two regions, the hollow center can be continuously varied. When such a hollow beam is used for surface processing, the thermal capillary effe

SUBMITTER: Wang Z 

PROVIDER: S-EPMC12038574 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature