215 research outputs found
Bianisotropic Effective Parameters of Optical Metamagnetics and Negative-Index Materials
Approaches to the adequate homogenization of optical metamaterials are becoming more and more complex, primarily due to an increased understanding of the role of asymmetric electrical and magnetic responses, in addition to the nonlocal effects of the surrounding medium, even in the simplest case of plane-wave illumination. The current trend in developing such advanced homogenization descriptions often relies on utilizing bianisotropic models as a base on top of which novel optical characterization techniques can be built. In this paper, we first briefly review general principles for developing a bianisotropic homogenization approach. Second, we present several examples validating and illustrating our approach using single-period passive and active optical metamaterials. We also show that the substrate may have a significant effect on the bianisotropic characteristics of otherwise symmetric passive and active metamaterials
Enhancement of spontaneous and stimulated emission of a rhodamine 6G dye by an Ag aggregate
We have demonstrated that by adding the solution of aggregated silver nanoparticles to the solution of rhodamine 6G dye, one can enhance the efficiency of spontaneous and stimulated emission. We attribute an increase of the spontaneous emission intensity of dye to the increase of the absorption efficiency caused by the field enhancements in metallic nanostructures associated with surface plasmons. The enhancement of the stimulated emission of dye, which has the same nature as the enhancement of absorption, was observed in the pump-probe and laser experiments
Dual-Band Negative Index Metamaterial: Double-Negative at 813 nm and Single-Negative at 772 nm
This work is concerned with the experimental demonstration of a dual-band
negative index metamaterial. The sample is double-negative (showing both a
negative effective permeability and a negative effective permittivity) for
wavelengths between 799 and 818 nm of linearly polarized light with a real part
of refractive index of about -1.0 at 813 nm; the ratio -Re(n)/Im(n) is close to
1.3 at that wavelength. For an orthogonal polarization, the same sample also
exhibits a negative refractive index in the visible (at 772 nm). The
spectroscopic measurements of the material are in good agreement with the
results obtained from a finite element electromagnetic solver for the actual
geometry of the fabricated sample at both polarizations.Comment: 3 pages, 4 figure
Recommended from our members
Plasmon coupled super- and sub- radiance from dye shells
Article investigates cooperative spontaneous emission, theoretically and experimentally, for an ensemble of emitters coupled to a core-shell structure
- …