Evolution and particle trapping dynamics of circular Pearcey-Airy Gaussian vortex beams in tightly focused systems.

Abstract

This study investigates the propagation and evolution of self-focusing circular Pearcey-Airy Gaussian vortex beams (CPAGVB) through high numerical aperture objective lenses. CPAGVB demonstrates a unique light field distribution compared to the circular Pearcey vortex beam and circular Airy Gaussian vortex beam. By adjusting optical distribution factors, main radii, and off-axis vortex pair positions, a variety of light field structures can be generated, including asymmetric micro-optical bottles, quasi-flat-top beam micro-optical bottles, and dual optical bottles. The particle trapping performance of CPAGVB is examined, revealing a gradient force eight orders of magnitude larger than its scattering force, up to twice the peak gradient force, and 2.5 times the scattering force of CAGVB. Further analysis of lateral power flow density, spin density vector, and total angular momentum distribution at the focal plane unveils the dynamics of particle motion toward the center. The Gouy phase difference under varying main radii reveals two types of normalized spin density vectors, characterized by helical and oscillating distributions. Additionally, the study examines the two-dimensional polarization ellipse distribution at the focal plane, elucidating the formation of central polarization singularities with axial vortices and the impact of peripheral polarization rearrangement on phase singularities. This research advances the comprehension of CPAGVB's distinctive properties and potential applications in micro-optical systems and particle manipulation.