Polarization properties of porous gold and silver films

Using the method of polarization modulation of electromagnetic radiation and the Kretschmann geometry, we perform comparative studies of surface plasmon resonance in porous and continuous gold and silver films. The spectral dependences of the polarization difference of the reflection coefficients of nano-composites are obtained for the first time and are supplemented by angular characteristics of this parameter. We show that these dependences characterize particular features of the optical properties related to the structure, morphology, and topology of porous films. We reveal that surface plasmon-polaritons and local plasmons in porous films can be excited both by radiation that is p polarized with respect to the plane of incidence, as is the case with continuous films, and by s polarized radiation. We demonstrate that the measurement results can yield information on the structural properties of films, such as their thickness, roughness height, degree of dispersion of nanoparticles, and so on.