0000000000115490
AUTHOR
Davy Gérard
Analysis of the Bloch mode spectra of surface polaritonic crystals in the weak and strong coupling regimes: grating-enhanced transmission at oblique incidence and suppression of SPP radiative losses
The Bloch mode spectrum of surface plasmon polaritons (SPPs) on a finite thickness metal film has been analyzed in the regimes of weak and strong coupling between SPP modes on the opposite film interfaces. The SPP mode dispersion and associated field distributions have been studied. The results have been applied to the description of the light transmission through thick and thin periodically structured metal films at oblique incidence. In contrast to normal incidence, all SPP Bloch modes on a grating structure participate in the resonant photon tunnelling leading to the transmission enhancement. However, at the angle of incidence corresponding to the crossing of different symmetry film SPP …
Étude en champ proche optique de cristaux photoniques bidimensionnels sur membrane suspendue
Nous presentons une etude experimentale en champ proche optique d'un cristal photonique 2D inscrit dans une membrane suspendue photoluminescente emettant a 1.5 μm. Les images obtenues mettent en evidence le guidage de la PL par la membrane, l'effet de bande interdite photonique ainsi que l'inhibition de l'emission de PL a l'interieur du cristal photonique.
Near-field probing of active photonic-crystal structures
We report a study of the optical near field of an active integrated component operating near the 1.55-mum telecommunications wavelength. The device is based on a two-dimensional photonic crystal etched in a suspended InP membrane. Topographic as well as optical information is collected by use of a scanning near-field optical microscope in collection mode, providing information about the local distribution of the losses.
Ridge-enhanced optical transmission through a continuous metal film
Optical transmission through a continuous (without holes) metal film with a periodic structure of metal or dielectric ridges on one or both interfaces was numerically studied. The dependencies of the transmission on the ridge width and height as well as the ridge arrangements on the opposite interfaces were investigated in weak- and strong-coupling regimes. The transmission enhancement was shown to depend on the relative position of the ridge gratings on the opposite interfaces of a film, confirming the role of resonant tunneling processes involving states of the surface polariton Bloch modes.
Suppression of radiative losses of surface polaritons on nanostructured thin metal films
The strong electromagnetic coupling between surface plasmon polariton modes on opposite interfaces of a finite thickness periodically nanostructured metal film has been studied. Surface polariton dispersion and associated electromagnetic field distributions have been analyzed. It was shown that at a frequency that corresponds to the crossing of film Bloch modes of different symmetries, the radiative losses of surface polaritons that are related to the polaritons' coupling to light during propagation on the structured surface are suppressed.
Experimental demonstration of Bloch mode parity change in photonic crystal waveguide
We experimentally show coupling between two photonic crystal waveguide Bloch modes having a different parity. A monomode ridge waveguide etched in a silicon-on-insulator substrate and connecting to the photonic crystal waveguide allows us to excite the even Bloch mode. Transmission measurements, performed on a broad spectral range, show the even mode propagation along the defect line. Then, spectrally resolved near-field patterns obtained by using a scanning near-field optical microscope in collection mode for wavelengths, inside and outside the multimode region of the photonic crystal waveguide, clearly demonstrate coupling phenomenon between even and odd modes.
Off-Resonant Optical Excitation of Gold Nanorods: Nanoscale Imprint of Polarization Surface Charge Distribution
International audience; We report on the nanoscale optical characterization of gold nanorods irradiated out of their plasmonic resonance. Our approach is based on the reticulation of a photopolymerizable formulation locally triggered by enhanced electromagnetic fields. The tiny local field enhancement stems from the surface polarization charges associated with the electric field discontinuity at the metal/dielectric interface. This allows us to get a nanoscale signature of the spatial distribution of the surface charge density in metallic nanoparticles irradiated off-resonance.
Sub-wavelength imaging of light confinement and propagation in SOI based photonic crystal devices
A light source is coupled into photonic crystal devices and a near field optical probe is used to observe the electromagnetic field propagation and distribution at a sub-wavelength scale. Bloch modes are clearly observed.
Far- and near-field characterization of a photonic-crystal-based microcavity on silicon-on-insulator
International audience
Near-field observation of subwavelength confinement of photoluminescence by a photonic crystal microcavity
We present a direct, room-temperature near-field optical study of light confinement by a subwavelength defect microcavity in a photonic crystal slab containing quantum-well sources. The observations are compared with three-dimensional finite-difference time-domain calculations, and excellent agreement is found. Moreover, we use a subwavelength cavity to study the influence of a near-field probe on the imaging of localized optical modes. © 2006 Optical Society of America.
Bloch mode coupling investigation in silicon-on-insulator W1 photonic crystal waveguide
We report in this paper the study of a W1 photonic crystal waveguide which supports two Bloch modes having different parity. A monomode ridge waveguide etched in a Silicon-On-Insulator substrate and connecting to the photonic crystal waveguide allows us to excite the even Bloch mode. Transmission measurements, performed on a broad spectral range, evidence the even mode propagation along the defect line and experimental spectrum is discussed in light of band diagram and FDTD calculations. Then spectrally resolved near-field patterns obtained by using a scanning near field optical microscope in collection mode for wavelengths inside and outside the multimode region of the photonic crystal wav…
Subwavelength imaging of field confinement in a waveguide-integrated photonic crystal cavity
A photonic crystal microcavity is designed to obtain an original field distribution inside the cavity and the structure is etched inside a silicon-on-insulator waveguide. Spectral location of the photonic band gap and cavity resonance are identified by using transmittance measurements and by analyzing the light collected by a scanning near-field optical microscope probe exactly positioned on the center of the cavity. The results obtained with the two techniques are in very good agreement. Then the near-field distribution above the device is mapped and light confinement inside the cavity is evidenced. Moreover, this confined light presents some remarkable patterns which clearly correspond to…
Bloch Modes Coupling in Photonic Crystal Waveguides
We investigate the properties of Bloch modes inside a photonic crystal waveguide. By using simultaneously a near field optical microscope and a transmittance setup, we demonstrate that Bloch modes having different parity are coupled.