Study on generation and propagation of polarization singularities based on circular swallowtail beams

In order to explore the polarization singular structures produced by combining circular swallowtail beams with polarization singularities, a method was adopted that introduced spiral phases into circular swallowtail beams and superimposing orthogonal circular polarization components, thereby generating multiple types of polarization singularities. Through theoretical analysis and numerical simulations, the self-focusing characteristics of the circular swallowtail vortex beam and the evolution of the beam’s intensity and phase under different amplitude parameters were systematically investigated. Furthermore, the topological stability of the resulting polarization singularities during free-space propagation was verified. The results showed that the polarization singularities carried by the optical field maintained a stable topological structure throughout propagation, unaffected by changes in amplitude parameters — differences only arose in local polarization state distribution and ellipticity. This study not only broadens the ways in which higher-order accelerating beams and polarization singularities can be integrated but also provides an important reference for the development of novel polarization control techniques in optical communications and related optical fields.