Abstract

Optical skyrmions have attracted increasing attention as topological light fields with potential applications in high-capacity optical information encoding, optical sensing, and precision micromanipulation. However, conventional free-space Stokes skyrmions based on Laguerre–Gaussian modes usually undergo passive topological-texture transformations during propagation due to the Gouy phase effect, which limits their stability and controllability. In this work, we demonstrate a versatile strategy for actively reconfiguring optical skyrmion topologies in free space. The main objective is to realize customizable Stokes skyrmions with controllable skyrmion number, texture helicity, and propagation trajectory while maintaining robust topological features over long propagation distances. By constructing structured vector beams from orthogonally polarized Bessel-mode components and implementing them through a spatial-light-modulator-based vector beam generator, we experimentally achieve propagation-invariant skyrmions with stable Néel-type textures. We further demonstrate programmable topological transformations, including skyrmion-to-anti-skyrmion conversion, skyrmion-to-bimeron transition, and stepwise switching among different topological orders. In particular, higher-order skyrmions with unchanged main-lobe radii are experimentally realized, corresponding to perfect optical skyrmions. In addition, we show that these skyrmionic beams can propagate along predefined self-accelerating trajectories, including spiral and parabolic paths, while preserving or dynamically transforming their topological textures. These results establish a robust and reconfigurable platform for manipulating topological light fields in free space, providing new opportunities for optical coding, encryption, sensing, and particle manipulation.

Biography

Dr. Weiming Zhen received his Ph.D. in Science from Nanjing University, China, in 2025, and is currently a postdoctoral researcher at Shenzhen University. He has published 20 papers in SCI-indexed journals and now serves as a Guest Editor for Photonics. His research focuses on optical field manipulation, spin–orbit coupling, and light–matter interactions.
Presenting author