Christophe Sauvan

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We design several single-photon-sources based on the emission of a quantum dot embedded in a semiconductor (GaAs) nanowire. Through various taper designs, we engineer the nanowire ends to realize efficient metallic-dielectric mirrors and to reduce the divergence of the far-field radiation diagram. Using fully-vectorial calculations and a comprehensive(More)
We measure the coherent scattering of light by a cloud of laser-cooled atoms with a size comparable to the wavelength of light. By interfering a laser beam tuned near an atomic resonance with the field scattered by the atoms, we observe a resonance with a redshift, a broadening, and a saturation of the extinction for increasing atom numbers. We attribute(More)
When a guided wave is impinging onto a Photonic Crystal (PC) mirror, a fraction of the light is not reflected back and is radiated into the claddings. We present a theoretical and numerical study of this radiation problem for several three-dimensional mirror geometries which are important for light confinement in micropillars, air-bridge microcavities and(More)
We provide a self-consistent electromagnetic theory of the coupling between dipole emitters and dissipative nanoresonators. The theory that relies on the concept of quasinormal modes with complex frequencies provides an accurate closed-form expression for the electromagnetic local density of states of any photonic or plasmonic resonator with strong(More)
The efficiency of conventional diffractive optical elements with échelette-type profiles drops rapidly as the illumination wavelength departs from the blaze wavelength. We use high dispersion of artificial materials to synthesize diffractive optical elements that are blazed over a broad spectral range (approximately 1 octave) or for two different(More)
We report on high-accuracy angle-resolved optical transmission measurements through anisotropic 2D plasmonic crystals made of gold films with large-area rectangular arrays of nanoscale square holes, deposited on GaAs substrates. The measurements reveal the dispersion relations of air-gold and gold-GaAs surface plasmon polaritons. The crystal anisotropy(More)
We theoretically study fishnet metamaterials at optical frequencies. In contrast with earlier works, we provide a microscopic description by tracking the transversal and longitudinal flows of energy through the fishnet mesh composed of intersecting subwavelength plasmonic waveguides. The analysis is supported by a semianalytical model based on(More)
Light emission by inelastic tunneling has been known for many years. Recently, this technique has been used to generate surface plasmons using a scanning tunneling microscope tip. The emission process suffers from a very low efficiency lower than a photon in 10^{4} electrons. We introduce a resonant plasmonic nanoantenna that allows both enhancing the power(More)
We present a semi-analytical formalism capable of handling the coupling of electromagnetic sources, such as point dipoles or free-propagating fields, with various kinds of dissipative resonances with radiation leakage, Ohmic losses or both. Due to its analyticity, the approach is very intuitive and physically-sound. It is also very economic in computational(More)
We propose a design to confine light absorption in flat and ultra-thin amorphous silicon solar cells with a one-dimensional silver grating embedded in the front window of the cell. We show numerically that multi-resonant light trapping is achieved in both TE and TM polarizations. Each resonance is analyzed in detail and modeled by Fabry-Perot resonances or(More)