Enhanced Focus Shaping of Circularly Polarized Laguerre–Gaussian Vortex Beams Using a Binary Axicon

The focus shaping of light beams is crucial for a range of optical applications, including trapping, imaging, and material processing. In this work, based on the vector diffraction theory, the focus shaping of a circularly polarized Laguerre–Gaussian vortex beam by a binary axicon was investigated. By analyzing the effects of beam parameters such as order p, topological charge m, truncation parameter β, and optical system characteristics including obstruction δ and NA, this study demonstrates how these factors influence the focal intensity distribution. By appropriately choosing specific parameters, different focal shapes, such as multifoci and double spots, were formed in the focal region of the binary axicon. The findings underscore the potential of binary axicons as versatile tools for advanced focus engineering in optical trapping and particle manipulation.