Optomagnetic composite medium with conducting nanoelements

Abstract

A new type of metal-dielectric composites has been proposed that is characterised by a resonance-like behaviour of the effective permeability eff µ in the infrared and visible spectral ranges. This material can be referred to as optomagnetic medium. It consists of conducting inclusions in the shape of non-closed contours or pairs of parallel sticks with length of 50-100 nm embedded in dielectric matrix. The analytical formalism developed is based on solving the scattering problem for considered inclusions with impedance boundary condition, which yields the current and charge distributions within the inclusions. The magnetic properties originated by induced currents are enhanced by localised plasmon modes, which make an inclusion resonate at a much lower frequency than that of the half-wavelength requirement at microwaves. It implies that microstructure can be made on a scale much less than the wavelength and the effective permeability is a valid concept. The presence of the effective magnetic permeability and its resonant properties lead to novel optical effects and open new possible applications. In particular, the condition for Brewster's angle becomes different resulting in reflectionless normal incidence from air (vacuum) if the effective permeability and permittivity are the same. The resonant behaviour of the effective permeability of the proposed optomagnetic medium could be used for creation of optical polarizes, filters, phase shifters, selective lenses.

Nanofabricated media with negative permeability at visible frequencies

“…In our experiments, we have also obtained an independent proof for magnetism at optical frequencies, beyond the discussed comparison between experimental and theoretical spectra (note that such comparison is widely accepted as standard -see, e.g., [13][14][15][16][17]). It is the observation of impedance matching that allowed us to confirm directly and qualitatively that our structures had large χ at green-light wavelengths.…”

Effects of disorder on subwavelength lensing in two-dimensional photonic crystal slabs

“…Recently, several authors have examined other types of possible structures, which could lead to LHM at infrared and visible frequencies [16][17][18].…”

Fine structure constant and quantized optical transparency of plasmonic nanoarrays

“…It is worth noting that the sizes of the nanopillars should be uniform over the whole sample and the thickness of natural oxide of the sublayer should be as small as possible and uniform. Similar regular highquality arrays have been used to realize ultra-narrow plasmonic resonances 9,10 , nanotweezing 11 , optomagnetic 12,13 and negative index metamaterials 14,15 .…”