Search results for "reflection"
showing 10 items of 645 documents
An ABM to support collective reflection on the evolution of mobility
2021
International audience; Transport infrastructures play a large part in defining a smart, sustainable and resilient city. Planning transportation systems traditionally rely on well-known evolutions of roads or public transportation (roundabouts for security, etc.). Yet, infrastructures might also benefit from, or may have to adapt to, recent disruptive innovations concerning modalities, technologies and societal organization (autonomous cars, smart infrastructure, homeworking, etc.). However, innovative urban policies might either facilitate mobility and increase citizen well-being, or create negative side effects. Urban planning therefore requires the city to assess the impact of these disr…
Near-field observation of subwavelength confinement of photoluminescence by a photonic crystal microcavity
2006
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.
Nonlinear femtosecond pulse propagation in all-solid photonic bandgap fiber
2009
Nonlinear femtosecond pulse propagation in all-solid photonic bandgap fiber is investigated experimentally and numerically for both the photonic bandgap guiding in the central silica core and the total internal reflection in germanium doped inclusions.
Analysis of the angular acceptance of surface plasmon Bragg mirrors
2007
International audience; We analyze an important aspect of the behavior of surface plasmon polariton (SPP) Bragg mirrors: the dependence of the angular acceptance for reflection on the incidence angle. By means of leakage radiation microscopy, both in direct and Fourier space, we observe that the angular acceptance diminishes for increasing incidence angles. This effect, which can considerably affect the design of devices based on these elements, is shown to be the consequence of the decrease of the bandgap width with increasing incidence angle. (c) 2007 Optical Society of America.
Dielectric-loaded plasmonic waveguide-ring resonators
2009
International audience; Using near-field microscopy, the performance of dielectric-loaded plasmonic waveguide-ring resonators (WRRs) operating at telecom wavelengths is investigated for various waveguide-ring separations. It is demonstrated that compact ( footprint similar to 150 mu m(2)) and efficient ( extinction ratio similar to 13 dB) WRR-based filters can be realized using UV-lithography. The WRR wavelength responses measured and calculated using the effective-index method are found in good agreement. (c) 2009 Optical Society of America
Bend- and splitting loss of dielectric-loaded surface plasmon-polariton waveguides.
2008
International audience; The design, fabrication, characterization, and modeling of basic building blocks of plasmonic circuitry based on dielectric- loaded surface polariton waveguides, such as bends, splitters, and Mach- Zehnder interferometers are presented. The plasmonic components are realized by depositing subwavelength dielectric ridges on a smooth gold film using mass-production- compatible UV-photolithography. The near-field characterization at telecommunication wavelengths shows the strong mode confinement and low radiation and bend losses. The performance of the devices is found in good agreement with results obtained by full vectorial three-dimensional finite element simulations.…
Near-field observation of surface plasmon polariton propagation on thin metal stripes
2001
International audience; We use a photon scanning tunneling microscope to probe the field of surface plasmon polariton modes excited on finite-width thin metal films (metal stripes). We first investigate the coupling between surface plasmons launched by a focused beam on a homogeneous thin film and the modes sustained by metal stripes of different widths. We show that. if the width of the metal stripe is about a few micrometers, a strong coupling with the stripe modes can be achieved at visible frequencies. A sharp transverse confinement of the field associated with the surface plasmon modes propagating on the metal stripe is unambiguously observed on the constant height photon scanning tunn…
Selective reflection spectroscopy of alkali vapors confined in nanocells and emerging sensing applications
2019
This thesis is aimed at studying the resonant interaction of a laser radiation with an atomic alkali vapor layer of wavelength-scale thickness confined in an optical nanocell; and emerging sensing applications.We focus our attention on the selective reflection arising at the interface between a dielectric window and a resonant alkali vapor, and show that the derivative of selective reflection spectra exhibit narrow resonances whose maxima are located exactly at atomic resonance frequencies. These resonances are observed with a spectral linewidth up to fifteen times smaller than the Doppler linewidth of the medium and their amplitudes scale linearly with respect to the transitions ones. Owin…
The Mistigri Thermal Infrared Project: Scientific Objectives And Mission Specifications
2013
ISI Document Delivery No.: 147NI Times Cited: 4 Cited Reference Count: 117 Cited References: Abrams M, 2000, INT J REMOTE SENS, V21, P847, DOI 10.1080/014311600210326 Agam N, 2007, J GEOPHYS RES-ATMOS, V112, DOI 10.1029/2007JD008407 Allen RG, 2007, J IRRIG DRAIN E-ASCE, V133, P380, DOI 10.1061/(ASCE)0733-9437(2007)133:4(380) Alletto L, 2006, CHEMOSPHERE, V64, P1053, DOI 10.1016/j.chemosphere.2005.12.004 Arnfield AJ, 2003, INT J CLIMATOL, V23, P1, DOI 10.1002/joc.859 Baschek B., 2010, 2010 OC SCI M PORTL Bastiaanssen WGM, 1998, J HYDROL, V212, P198, DOI 10.1016/S0022-1694(98)00253-4 Bastiaanssen WGM, 2005, J IRRIG DRAIN E-ASCE, V131, P85, DOI 10.1061/(ASCE)0733-9437(2005)131:1(85) Beck LR, 2…
Experimental and theoretical studies on electropolymerization of polar amino acids on platinum electrode
2017
International audience; The anodic oxidation of polar amino acids (L-serine, L-threonine, L-asparagine, and L-glutamine) in aqueous electrolyte on smooth platinum electrode was carried out by cyclic voltammetry coupled to electrochemical quartz crystal microbalance (EQCM). pH (zwitterion, acidic and alkaline) effects on their electrochemical behavior were examined. The maximum current values are measured for zwitterion species. In addition, the current increases with increasing of concentration and scan rate, and decreases with increasing pH. The resulting passivation was studied by spectroscopic analysis such as attenuated total reflection FT infrared spectroscopy (ATR-FTIR), X-ray photoel…