Autofocusing capabilities of double-ring circular Airy Gaussian beams and their application in particle manipulation

Focusing is extensively researched in bioimaging, medicine, and quantum computation. However, single focal point and short focal length restrict imaging and optical manipulation at long distances. In this study, we propose what we believe to be a novel method, namely the coherent superposition of double-ring circular Airy Gaussian beams (DR-CAiGBs) to achieve multiple autofocusing over long distances. Without complex structures, theoretical simulations and experimental verifications demonstrate that the DR-CAiGBs can generate multiple autofocusing points along the optical axis, whose positions and quantities can be flexibly adjusted. Furthermore, we demonstrated the two-dimensional (2D) particle manipulation of the DR-CAiGBs by trapping multiple particles at different autofocusing points over 100 µm. Our research and findings establish new avenues for practical applications in biological cell analysis, particle transportation, and lithography.