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107
Experimental demonstration of frequency-agile terahertz metamaterials
- Nature Photon
, 2008
"... Metamaterials exhibit numerous novel effects1–5 and operate over a large portion of the electromagnetic spectrum6–10. Metamaterial devices based on these effects include gradientindex lenses11,12, modulators for terahertz radiation13–15 and compact waveguides16. The resonant nature of metamaterials ..."
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Cited by 25 (4 self)
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Metamaterials exhibit numerous novel effects1–5 and operate over a large portion of the electromagnetic spectrum6–10. Metamaterial devices based on these effects include gradientindex lenses11,12, modulators for terahertz radiation13–15 and compact waveguides16. The resonant nature of metamaterials results in frequency dispersion and narrow bandwidth operation where the centre frequency is fixed by the geometry and dimensions of the elements comprising the metamaterial composite. The creation of frequency-agile metamaterials would extend the spectral range over which devices function and, further, enable the manufacture of new devices such as dynamically tunable notch filters. Here, we demonstrate such frequency-agile metamaterials operating in the far-infrared by incorporating semiconductors in critical regions of metallic split-ring resonators. For this first-generation device, external
A Subwavelength Plasmonic Metamolecules
"... The lack of symmetry between electric and magnetic charges, a fundamental consequence of the small value of the fine-structure constant1, is directly related to the weakness of magnetic effects in optical materials2,3. Properly tailored plasmonic nanoclusters have been proposed recently to induce ar ..."
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Cited by 6 (0 self)
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The lack of symmetry between electric and magnetic charges, a fundamental consequence of the small value of the fine-structure constant1, is directly related to the weakness of magnetic effects in optical materials2,3. Properly tailored plasmonic nanoclusters have been proposed recently to induce artificial optical magnetism4–7 based on the principle that magnetic effects are indistinguishable from specific forms of spatial dispersion of permittivity at optical frequen-cies1. In a different context, plasmonic Fano resonances have generated a great deal of interest, particularly for use in sensing applications that benefit from sharp spectral features and extreme field localization8–12. In the absence of natural magnetism, optical Fano resonances have so far been based on purely electric effects. In this Letter, we demonstrate that a subwavelength plasmonic metamolecule consisting of four
Imaging interferometric microscopy
, 2007
"... Imaging interferometric microscopy (IIM) is a synthetic aperture imaging approach providing resolution to the transmission medium (refractive index n) linear systems limit extending to ��/4n using only low-numericalaperture (low-NA) optics. IIM uses off-axis illumination to access high spatial frequ ..."
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Cited by 5 (1 self)
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Imaging interferometric microscopy (IIM) is a synthetic aperture imaging approach providing resolution to the transmission medium (refractive index n) linear systems limit extending to ��/4n using only low-numericalaperture (low-NA) optics. IIM uses off-axis illumination to access high spatial frequencies along with interferometric reintroduction of a zero-order reference beam on the low-NA side of the optical system. For a thin object normal to the optical axis, the frequency space limit is ��1+NA�n/��, while tilting the object plane allows collection of diffraction information up to the material transmission bandpass-limited spatial frequency of 2n/�. Tilting transforms the spatial frequencies; the algorithm to reset to the correct image frequencies is described. IIM involves combining multiple subimages; the image reconstruction procedures are discussed. A mean-square-error metric is introduced. For binary objects, sigmoidal filtering of the image provides significant
Absolute extinction cross-section of individual magnetic split-ring resonators
- Nat. Photonics
, 2008
"... Complete control of an electromagnetic wave requires access to its electric and magnetic vector components. Realizing this level of control with metamaterials has recently opened new avenues regarding negative refractive indices1,2 and invisibility cloaking3,4. The required microscopic building bloc ..."
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Cited by 3 (1 self)
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Complete control of an electromagnetic wave requires access to its electric and magnetic vector components. Realizing this level of control with metamaterials has recently opened new avenues regarding negative refractive indices1,2 and invisibility cloaking3,4. The required microscopic building blocks are artificial electric and magnetic dipoles. Magnetic dipoles oscillating at optical frequencies have become available only recently in the form of man-made split-ring resonators5, essentially subwavelength resonant electromagnets. Previous experimental work has focused on arrays of electric and/or magnetic dipoles1,2,6,7. For further developments in this field, knowledge of the properties of the individual dipoles is highly desirable. In this paper, using a modulation technique8,9, we measure the absolute extinction cross-section of a single split-ring resonator for the first time. At the fundamental magnetic
Volume integral equations for scattering from anisotropic diffraction gratings
- Mathematical Methods in the Applied Sciences
, 2012
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Correct Definition of the Poynting Vector in Electrically and Magnetically Polarizable Medium Reveals that Negative Refraction is Impossible
, 2008
"... I compute from first principles the local heating rate q (the amount of electromagnetic energy converted to heat per unit time per unit volume) for electromagnetic waves propagating in magnetically and electrically polarizable media. I find that, in magnetic media, this rate has two separate contrib ..."
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Cited by 2 (0 self)
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I compute from first principles the local heating rate q (the amount of electromagnetic energy converted to heat per unit time per unit volume) for electromagnetic waves propagating in magnetically and electrically polarizable media. I find that, in magnetic media, this rate has two separate contributions, q (V) and q (S), the
