Tailoring Skyrmions and Total Angular Momentum Beams in Kilometer‐Scale Few‐Mode Fibers

ABSTRACT Complex vector fields such as Stokes skyrmions and total angular momentum (TAM) beams exhibit revolutionary potential in applications including communications, quantum information processing, and computing. However, beam diffraction and turbulence in free space restrict their controllability to short distances. Here, we propose and experimentally validate a novel framework that manipulates vector fields in a 2‐km few‐mode fiber (FMF) using only intensity measurements. We comprehensively demonstrate the accuracy and effectiveness of this approach, achieving (i) Stokes skyrmions with an average deviation in skyrmion number of only 0.65%; (ii) high‐dimensional superposition states with an average fidelity exceeding 98% constructed using TAM beams; and (iii) orbital angular momentum (OAM) and cylindrical vector (CV) modes with maximum (mean) purities of 99% (94%). In addition, we introduce a phase‐fluctuation‐resistant characterization method for skyrmions. By eliminating the need for phase detection in conventional schemes, our framework enables seamless switching across mode groups and wavelengths without any receiver‐side optical realignment and offers compatibility with diverse mode‐division multiplexing systems. This approach offers an accurate, fast, scalable, and cost‐effective solution for long‐distance control of structured light fields, and demonstrates strong potential for higher‐dimensional structured light customization.