Fig. 2

(a) Sketch of the Kretschmann-Raether configuration. The prism is quoted and the radiation wavevector \(\varvec{k}\) has been decomposed in its parallel, \(\varvec{\beta}\), and perpendicular, \({\varvec{k}}_{\varvec{x}}\), components. (b) Sketch of the experimental apparatus. FTIR Infrared source (FTIR IR source); plane mirror (PM); focusing mirror (FM); iris (I); Kretschmann-Raether configuration (KR); rotational motorized stage (MS); the polarizer (P) tuned to 45°; analyzer (A).