Optical quasicylindrical waves at dielectric interfaces

Choon How Gan (1) , Loïc Lalouat (2) , Philippe Lalanne (3, 1) , Lionel Aigouy (2)

1 Laboratoire Charles Fabry de l'Institut d'Optique / Naphel
2 LPEM - Laboratoire de Physique et d'Etude des Matériaux (UMR 8213)
3 lp2n-03,lp2n-13

Much effort has been recently devoted to the study of the electromagnetic field launched on a metal-dielectric interface by one-dimensional (1D) subwavelength indentations. In this work, we consider the wave launched on a semiconductor surface that does not support any surface modes, in contrast to the metallic case. Through analytical calculations performed for polarized 2D Dirac line sources, we show that the waves launched by the two orthogonal polarizations (parallel and perpendicular to the surface) have approximately the same form, differing only in phase and magnitude. This finding implies that the wave launched on the surface by an arbitrary subwavelength indentation under an arbitrary illumination, either at grazing, normal, or oblique incidence, is always the same and possesses universal characteristics.We further observe this wave on a silicon substrate with a near-field probe. Through fitting with a simple model, the measured field is found to exhibit characteristics that are reminiscent of quasicylindrical waves on metal surfaces.

Domaines: Optique / photonique; Optique [physics.optics]

Choon How Gan, Loïc Lalouat, Philippe Lalanne, Lionel Aigouy. Optical quasicylindrical waves at dielectric interfaces. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2011, 83, pp.085422. ⟨10.1103/PhysRevB.83.085422⟩. ⟨hal-00679146⟩