Effect of roughness on surface plasmons propagation along deep and shallow metallic diffraction gratings

The roughness of shallow or deep metallic diffraction gratings modifies the propagation of surface plasmon mode along the metallic-air interface. The scattering losses lead to a spectral or angular broadening of the surface plasmon resonance (SPR) and to a shift of the resonance wavelength and coupling angle. This mechanism is deeply analyzed both experimentally and theoretically to overcome these effects when such structures, in particular deep ones, are used as SPR-based sensors. (C) 2022 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

This study deeply analyzes the influence of the roughness of shallow or deep metallic diffraction gratings on the propagation of surface plasmon mode along the metallic-air interface. It is found that the scattering losses lead to a spectral or angular broadening of the surface plasmon resonance (SPR) and a shift of the resonance wavelength and coupling angle. These effects need to be overcome when using such structures, especially deep ones, as SPR-based sensors.