Sculpting the focusing morphologies of tightly focused dual-ring Airy-Gaussian beam via vortex

Precise manipulation techniques for complex optical fields in the focal space have remained a key research priority due to their critical role in cutting-edge fields such as optical micromanipulation. This paper achieves multimodal customized modulation of continuous optical bottle (COB) and multi-point focusing structures generated by dual-ring Airy-Gaussian vortex beams (DRAGVB) under tightly focused conditions. When the topological charges of the inner and outer ring satisfy l1 = l2, COBs can be induced, thereby revealing the physical mechanisms governing the participation of core parameters in the construction of COB structure, as well as the modulation of intensity distribution and phase profile. The focal length f of the tightly focused system can modulate the axial coiling-uncoiling and radial expansion-contraction of the COB. As one of the two parameters of the dual-ring configuration, the inner ring radius r0 controls the axial length of the COB and the peak intensity on the focal plane. The other parameter of the dual-ring configuration, the outer-to-inner ring radius ratio β, enables linear tuning of the flatness of the COB within the range of β = 1.2–1.7. The width factor b controls the number of sub-optical bottles within the COB. The values of l1 = l2 determine the number of vortex spiral turns in the focal plane, and their increase drives energy to diffuse into multi-ring zones. When l1 ≠ l2, DRAGVB generates a multi-point focusing structure with |l2 − l1| focal spots. Furthermore, within a certain range where l1 = −l2, increasing the topological charges gradually evolves into a well-defined dual-ring focusing structure. This study establishes a quantitative basis for customized modulation of the tightly focused DRAGVB, enriching the theory of tight-focusing regulation of vortex-type complex structured light. It provides a robust theoretical foundation for high-precision trapping and multi-particle parallel manipulation in optical micromanipulation.