Biomedical subjects

G Colas Des Francs

Publications and source records attributed to G Colas Des Francs.

3 recordsLinked to original sources

PubMed2002

Imaging the local density of states of optical corrals.

This paper reports the experimental observation, at optical frequencies, of the electromagnetic local density of states established by nanostructures corresponding to the recently introduced concept of optical corral [G. Colas des Francs et al., Phys. Rev. Lett. 86, 4950 (2001)]. The images obtained by a scanning near-field optical microscope under specific operational conditions are found in agreement with the theoretical maps of the optical local density of states. A clear functionality of detection by the scanning near-field optical microscope is thereby identified since the theoretical maps are computed without including any specific tip model.

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PubMed2001

Optical analogy to electronic quantum corrals.

We describe full multiple-scattering calculations of localized surface photonic states set up by lithographically designed nanostructures made of a finite number of dielectric pads deposited on a planar surface. The method is based on a numerical solution of the dyadic Dyson's equation. When the pads are arranged to form a closed circle, we find field patterns that look like the electronic charge density recently observed above quantum corrals. We propose two experimental techniques that could be used to observe these electromagnetic modes in direct space.

Journal Article↗

PubMed2001

Near-field optical probing of two-dimensional photonic crystals: theory and experiment.

We report new experimental results, and their theoretical analysis, on the mechanisms that control light transfer between two integrated waveguides connected by two-dimensional matrices of dielectric pillars. The optical properties of the system are analysed from the well-established formalism of classical field susceptibilities (Green dyadic functions). We apply this scheme to investigate the optical properties of two-dimensional arrays connected to two integrated waveguides. Comparisons with current experimental work based on near-field optical probing are provided together with a spectral analysis of the phenomenon.

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