Enhanced diffraction from a grating on the surface of a negative-index metamaterial.
We show by numerical simulation as well as by measurements on negative-index metamaterial wedge samples, that the unavoidable stepping of the refraction interface-due to the finite unit-cell size inherent to metamaterials-can give rise to a well-defined diffracted beam in addition to the negatively refracted beam. The direction of the diffracted beam is consistent with elementary diffraction theory; however, the coupling to this higher order beam is much larger than would be the case for a positive index material. The results confirm recent theoretical predictions of enhanced diffraction for negative-index grating surfaces.
Smith
D R
DR
Department of Physics, University of California, San Diego, La Jolla, California 92093, USA.
Rye
P M
PM
Mock
J J
JJ
Vier
D C
DC
Starr
A F
AF