Краткое описание

Using the coupled wave method an absorption of electromagnetic waves in a grating-metallic substrate system has been analyzed, in the problem a grating can be both dielectric and metallic. It is proved that at certain wavelength resonance of plasmons can be achieved. That results in completed absorption of electromagnetic wave by the system. For comparison the research of plasmons resonance excited by a prism into thin silver film has been carried out. It is found that on certain conditions a total absorption can be attained. In this conditions the strong dependence on incidence angle at metallic film has been observed within resonance range. It is shown that for both methods of plasmons excitation within the resonance range the identical dependences of reflectance on refraction index of medium, which contacts directly with gratings and thin metallic film, has been observed; as this takes place the refractive index change by 0.001 results in variation of the reflection coefficient from zero to 0.8.