Analytic design and visualization of multiple surface plasmon resonance excitation using angular spectrum decomposition for a Gaussian input beam

We propose an exact design, analysis, and visualization method for multiple surface plasmon resonance (MSPR) mode excitation phenomena for a structure composed of an optimized-thickness polymethyl-methacrylate layer and a gold thin-film layer. The proposed simulation method is based on a recursive transfer matrix method (R-TMM) and Gaussian angular spectrum decomposition. Our method illustrates, under the Kretchmann-Raether attenuated total reflection (ATR) geometry, the response for an angle-modulated Gaussian incident beam. To verify the simulation results we also performed experiments to excite MSPR modes under the ATR geometry. Our fast and exact R-TMM with the Gaussian angular spectrum method can be widely applied to the design and analysis of metal- and dielectric-composed thin film structures.