Plasmonic concentrator of magnetic field of light

• We propose an efficient concentrator of the magnetic component of evanescent field of light for measuring magnetic responses of nanostructures. It is in the form of a tapered fiber probe, which in its final part has corrugations along the angular dimension and is coated with metal except for the aperture at the tip. Internal, azimuthally polarized illumination is concentrated into a subwavelength spot with a strong longitudinal magnetic component H-z. Within the visual range of wavelengths 400-700 nm, the energy density of H-z is up to 50 times larger than that of the azimuthal electric E-phi one. This dominant H-z contribution may be used for magnetic excitation of elementary cells of metamaterials with a single probe guiding a wide spectrum of generated plasmons.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

optical microscope

tip

wave-guides

permittivity

frequencies

permeability

propagation

near-field

split-ring resonators

metamaterials

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)