Direct imaging of radiative decay of surface plasmon polaritons in nanohole arrays by cross-polarization microscopy

摘要

We employ angle- and polarization-resolved optical microscope to image the radiative decay patterns of surface plasmon polaritons (SPPs) in Au nanohole array. By controlling the incident angle, we excite desired SPP mode and image its radiative decay under cross-polarization configuration. The experimental results are supported by temporal coupled mode theory and confirmed by finite-difference time-domain simulations and analytical calculations. Our approach is effective in studying the decay process of any particular SPP mode in periodic structures and thus is useful in understanding SPP mediated Raman scattering and fluorescence.