Surface plasmon resonance excitation and imaging in circular gratings: a study of non-polarized, radial and azimuthal polarization effects

This study explores the effects of various polarization states on surface plasmon resonance (SPR) in circular gratings, emphasizing their potential in sensing technologies. We present a mathematical modeling framework alongside experimental investigations involving the fabrication and characterization of circular gratings using linearly polarized, radially polarized, and non-polarized light. Our findings demonstrate stable SPR responses across multiple polarization angles, with strong signals achievable even with non-polarized light, minimizing reliance on polarizers. Additionally, we analyze spatial intensity responses and the influence of polarization on excitation patterns, enhancing our understanding of plasmonic interactions. Through Surface Plasmon Resonance imaging (SPRi), we highlight the capability to capture topographical information, further contributing to advancements in plasmonics and the development of improved sensing devices.