7 research outputs found
Electromagnetic wave diffraction by periodic planar metamaterials with nonlinear constituents
We present a theory which explains how to achieve an enhancement of nonlinear
effects in a thin layer of nonlinear medium by involving a planar periodic
structure specially designed to bear a trapped-mode resonant regime. In
particular, the possibility of a nonlinear thin metamaterial to produce the
bistable response at a relatively low input intensity due to a large quality
factor of the trapped-mode resonance is shown. Also a simple design of an
all-dielectric low-loss silicon-based planar metamaterial which can provide an
extremely sharp resonant reflection and transmission is proposed. The designed
metamaterial is envisioned for aggregating with a pumped active medium to
achieve an enhancement of quantum dots luminescence and to produce an
all-dielectric analog of a 'lasing spaser'.Comment: 18 pages, 13 figure
Optical manifestations of planar chirality
We report that planar chiral structures affect the polarization state of light in a manner similar to three-dimensional chiral (optical active) media. In experiments with artificial metal-on-silicon chiral planar gratings of 442 wallpaper group symmetry, containing millions of chiral elements per square centimeter, we observed rotation of the polarization azimuth in excess of 30_ of light diffracted from it. The rotation was found to change its sign for two enantiomeric forms of the media and to have components associated with both the structural arrangement and the chirality of individual structural elements