Manipulation of plasmonic skyrmions and merons by tuning linearly polarized light

Plasmonic topological quasiparticles are highly promising for multi-channel data parallelization and transmission with the modulation degrees of freedom of polarization, phase, and spin angular momentum. In this study, we propose and demonstrate a polarization-sensitive catenary-shaped nanostructure combined with nano-slits for the generation of plasmonic topological quasiparticles as well as active manipulation of the types. The field distribution of topological quasiparticles measured by near-field scanning optical microscopy with p- and s-polarized light is consistent with a finite-difference time-domain simulation. By analyzing the vector textures and skyrmion number, the generation of plasmonic skyrmion and meron is confirmed, exhibiting the switching between the two topological quasiparticles by rotating the polarization direction of the incident laser.