Surface lattice resonances in axisymmetric plasmonic nanoarrays for vector optical field manipulation

Surface lattice resonances (SLRs), arising from coherent coupling among localized surface plasmon resonances in periodic metallic nanostructures, offer narrow linewidths and high quality factors, making them promising for high-precision photonic applications. While most studies focus on translationally symmetric arrays, axisymmetric configurations remain underexplored. Here, we establish a general dipole-sum-based analytical model to describe SLRs in rotationally symmetric nanoarrays and demonstrate their utility in vector optical field (VOF) manipulation. We investigate both circular and helical nanoarrays, achieving an ultrahigh Q-factor of ∼103 and a narrow linewidth of 0.55 nm in an optimized single-ring structure with polarization-independent resonant responses. Furthermore, we show that helical arrays support orbital angular momentum (OAM)-selective excitation and spin-insensitive helical dichroism under resonance conditions. This work provides fundamental insights into axisymmetric SLRs and offers a robust platform for integrated VOF generation and chiral sensing.