Active Reshaping of Plasmonic Meron Pattern With Rotating Polarization Direction of the Incident Light

ABSTRACT We propose a polarization‐dependent catenary‐groove composite nanostructure for achieving active modulation of plasmonic merons with linearly polarized light. By simply varying the polarization direction, both the quantity and spatial distribution of merons can be controlled within the proposed structure. With p‐polarized light excitation, stripe‐like hotspot pattern is excited, while periodic hotspot lattices can be produced under the excitation of s‐polarized light. The patterns of field intensity within the composite structure are confirmed by the consistent results from near‐field scanning optical microscopy (NSOM) measurement and finite‐difference time‐domain (FDTD) simulation. Topological properties of the excited hotspots, i.e., plasmonic merons, are identified by the analysis of vector texture of the electric field and skyrmion number. Furthermore, the mechanisms responsible for the different patterns of plasmonic merons are revealed through momentum‐space analysis of the excited SPPs. These results demonstrate that polarization can provide another degree of freedom for tuning plasmonic meron lattices, offering a versatile strategy for extending its application in the fields of secure encryption, high‐density data storage, and parallel information processing. This provides a new paradigm for encoding electromagnetic information through spatially programmable plasmonic topological structures.