摘要
Topological spin textures in plasmonic fields open pathways to robust nanophotonic architectures, yet excitation rarely achieves perfect circular polarination. Real‑world inputs depart from ideal RCP or LCP: changes in amplitude or phase between orthogonal polarization axes produce ellipticity, yet the spin texture is preserved. Beyond classical spin-momentum locking of evanescent waves we reveal a new selection law: for any elliptical input state the near‑field meron lattice maps a single dominant circular channel, chosen by the incident state’s hemisphere on the Poincaré sphere. We use a square‑slit aperture on a metal-dielectric interface and combine full‑vector simulation with analytical theory. Experimental verification via L‑line measurements is underway. These findings establish ellipticity‑robust topological plasmonics and provide practical guidance for skyrmion/meron devices operating far from ideal inputs.