Resonant scattering of light measurements from a system with rough interfaces that supports guided modes.

We reported experimental results of the resonant scattering of light from a system prism-glass/Ag/MgF2/air in the ATR-Kretschmann configuration, for p-polarized light incident by the glass side. The thickness of the dielectric film is chosen in such a way that in the absence of roughness the system supports 3 transverse magnetic (TM) guided modes, at a wavelength λ = 632.8 nm of the incident light. The scattering is due to the natural roughness of each interface of the system, while the resonant character of the scattering is due to the excitation of the guided modes and their interaction with the interfaces roughness. The scattered light shows six peaks at angles given by θ1 = ± 61.65 0, θ2 = ± 53.69 0, and θ3 = ± 43.40 0, for any angle of incidence. These angles correspond to the excitation of the guided modes. The scattering response is enhanced when the angle of incidence is equal to one of the angles of excitation of the guided modes.