Properties of nanostructured metamaterials at optical frequencies

• A variety of metamaterials has been demonstrated recently that support backward waves and negative refraction (Negative Index Materials, NIM.) In particular, these materials enable sub-wavelength resolution that makes them even more interesting, especially in optical domain rather than at microwave frequencies where their unusual properties were known for decades. We describe below theoretical and experimental studies of the so-called 'fishnet' metal-spacer holearray metamaterials, which exhibit NIM behavior at optical frequencies, having unit cell size of a few 100s nm. We demonstrate experimentally that their refractive index can be modulated very fast and very strongly (from -2.4 to -1.5) around the communication wavelength of =1.55 um, in good agreement with the FDTD results. We also discuss a problem of loss compensation in those materials with hefty Ohmic losses by using gain media and local field enhancement in metallic nanoparticles ensembles that enable SERS.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Nanoteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Nano-technology (hsv//eng)

Nyckelord

Backward wave

Extraordinary transmission

Metamaterial

Negative Index

Ohmic losses

Optical frequencies

Surface enhanced raman spectroscopy (sers)

Light refraction

Light transmission

Natural frequencies

Optical materials

Optoelectronic devices

Raman scattering

Raman spectroscopy

Rectangular waveguides

Refractive index

Spectrum analysis

Surfaces

Wave transmission

Metamaterials

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