Concept

Miroir sphérique

Publications associées (131)

Nanometer focusing properties of Fresnel zone plates described by dynamical diffraction theory

The x-ray focusing properties of linear Fresnel zone plates have been derived by solving the Helmholtz equation for the field propagating through the zones. We consider the imaging of a point object into the first diffraction order of a volume zone plate h ...

2006

Fast 10-µs Microelectromechanical Optical Switch inside Planar Hollow Waveguide (PHW)

Philippe Renaud

A new concept for a 1 × 2 micromechanical optical switch with 10 μs of switching speed, 29 dB of ON/OFF ratio, and insertion loss of −7.22 dB for λ = 1550 nm and −4.96 dB for λ = 635 nm is presented. The idea is to insert a micromechanical switching mechan ...

2006

From Mirroring to Guiding: A Review of State of the Art Technology for Supporting Collaborative Learning

Patrick Jermann

We review a representative selection of systems that support the management of collaborative learning interaction, and characterize them within a simple classification framework. The framework distinguishes between mirroring systems, which display basic ac ...

2005

Multiple scattering in optical coherence tomography. I. Investigation and modeling

Theo Lasser, Boris Clément Karamata, Marcel Leutenegger, Stéphane Bourquin, Markus Laubscher

We present a new model of optical coherence tomography (OCT) taking into account multiple scattering. A theoretical analysis and experimental investigation reveals that in OCT, despite multiple scattering, the field backscattered from the sample is general ...

2005

Laplacian Operator, Diffusion Flow and Active Contour on non-Euclidean Images

Jean-Philippe Thiran, Pierre Vandergheynst, Xavier Bresson, Iva Bogdanova Vandergheynst

We propose here some basic approaches to direct processing of the

360^o

-images as we take into consideration the geometry of each one. Obviously, the geometry of each of these images is a consequence of the geometry of the sensor's mirror used. This tech ...

2005

An alternative ECRH front steering launcher for the ITER upper port

René Chavan, Francisco Sanchez

Presently, a remote steering (RS) antenna [C.P. Moeller, A method of remotely steering a microwave beam launched from a highly overmoded corrugated waveguide, in: Proceedings of the 23rd International Conference on IRMMW, Colchester, UK, 1998] is envisione ...

2005

Phase shifted microcavities

Ross Stanley

An optically-active multi-layer dielectric structure comprises an optically active zone between two mirrors forming a Fabry-Perot microcavity. The optically active zone comprises an optically active material of wavelength lambda centred in a layer of high ...

2004

Wavelength dependent optical force on elliptical silver cylinders at plasmon resonance

Hans Peter Herzig

We use rigorous diffraction theory to analyze the force on elliptical cylinders made from silver as a function of the elongation. We find that, when the wires are illuminated at the plasmon wavelength and placed in a highly focused Gaussian beam, they are ...

2004

Resonator stability subject to dynamic random-tilt aberration

Theo Lasser, Max-Olivier Hongler

We derive the behavior of the average exit time (i.e., the number of reflections before escape) of a ray path traveling between two perfect mirrors subject to dynamic random-tilt aberrations. Our calculation is performed in the paraxial approximation. When ...

2003

Strong coupling in high-finesse organic semiconductor microcavities

Raphaël Butté

We report the fabrication of high-finesse strongly coupled microcavities composed of a polystyrene film doped with the dye tetraphenyl-porphyrin zinc positioned between two high reflectivity dielectric mirrors. The bottom mirror was deposited by plasma enh ...

American Institute of Physics2003

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Laplacian Operator, Diffusion Flow and Active Contour on non-Euclidean Images

Jean-Philippe Thiran, Pierre Vandergheynst, Xavier Bresson, Iva Bogdanova Vandergheynst

We propose here some basic approaches to direct processing of the

360^o

-images as we take into consideration the geometry of each one. Obviously, the geometry of each of these images is a consequence of the geometry of the sensor's mirror used. This tech ...

2005