Free-electron coupling to surface polaritons mediated by small scatterers.

ABSTRACT: The ability of surface polaritons (SPs) to enhance and manipulate light fields down to deep-subwavelength length scales enables applications in optical sensing and nonlinear optics at the nanoscale. However, the wavelength mismatch between light and SPs prevents direct optical excitation of surface-bound modes, thereby limiting the widespread development of SP-based photonics. Free electrons are a natural choice to directly excite strongly confined SPs because they can supply field components of high momentum at designated positions with subnanometer precision. Here, we theoretically explore free-electron-SP coupling mediated by small scatterers and show that low-energy electrons can efficiently excite surface modes with a maximum probability reached at an optimum surface-scatterer distanc

SUBMITTER: Prelat L 

PROVIDER: S-EPMC11614564 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature