ABSTRACT Precise control of light polarization at the nanoscale is critical for accessing chiral optical responses and manipulating spin–photon interactions in advanced materials. Yet, conventional scattering‐type near‐field probes predominantly generate out‐of‐plane linear polarization and offer little control over phase or polarization state. Here, we introduce a polarization‐engineered near‐field methodology based on a combined metallic tip and planar dipole nanoantenna system. Using full‐wave electromagnetic simulations, we show that the tip acts as a vertically oriented plasmonic resonator, while the antenna supports an in‐plane dipolar mode. By tuning the tip–antenna geometry and tip height, the two orthogonal field components attain comparable amplitudes and a controllable ∼90° phase offset, producing circularly polarized nano‐light in the antenna gap. The proposed system effectively functions as a nanoscale quarter‐wave plate, converting linearly polarized illumination into circularly polarized hotspots without external polarization optics. This method establishes an experimentally accessible route toward polarization‐programmable near‐field nanoscopy, enabling chiral spectroscopy, selective excitation of spin/valley degrees of freedom, and quantum optical investigations at the nanoscale.
Dai et al. (Wed,) studied this question.