Total light absorption in a wide range of incidence by nanostructured metal without plasmons

Nicolas Bonod (1) , E. Popov (1)

1 FRESNEL - Institut FRESNEL

Metals structured by nanocavities have recently been demonstrated to efficiently absorb light in a wide range of angle of incidence. It has been assumed that nanovoid plasmons are at the origin of the strong absorption. It is shown in this paper that it is possible to totally absorb incident light without plasmons. To avoid their excitation, a diffraction grating consisting of cylindrical cavities in a metallic substrate is illuminated in transverse electric (TE) polarization. It is found that cylindrical cavities can sustain cavity resonances with a high enhancement of the light intensity, provoking a total absorption of light in a wide range of incidence.

Mots clés: Diffraction and gratings : Diffraction gratings; Physical optics : Metal optics; Diffraction and gratings : Resonance domain; Optics at surfaces : Surface plasmons

Domaines: Optique / photonique

Nicolas Bonod, E. Popov. Total light absorption in a wide range of incidence by nanostructured metal without plasmons. Optics Letters, 2008, 33 (20), pp.2398-2400. ⟨hal-00330211⟩