Resonance excitation of surface electromagnetic waves on diffraction gratings in the IR region: anomalies of absorption and reflection

Absorption of the IR radiation by metallic diffraction gratings was studied by using the optoacouatic effect. Narrow peaks that correspond to resonance excitation of surface electromagnetic waves (SEW) were discovered. The dependence of peak widths was investigated as a function of the SEW pathlength and the width of the angular spectrum of radiation. The macroscopic redistribution of radiation intensity was discovered experimentally in the beam specularly reflected from the grating.