Search results for "plasmon"

Surface plasmon interference fringes in back-reflection

2010

We report the experimental observation of surface plasmon polariton (SPP) interference fringes with near-unity visibility and half-wavelength periodicity obtained in back reflection on a Bragg mirror. The presented method based on leakage radiation microscopy (LRM) represents an alternative solution to optical near-field analysis and opens new ways for the quantitative analysis of SPP fringes. With LRM we investigate various SPP interference patterns and analyze the high reflectivity of Bragg mirror in comparison with theoretical models.

Influence of spectral composition on the temperature coefficients of solar cells from Elkem Solar

2014

The temperature coefficients of solar cells from two different feedstocks — a compensated silicon, the Elkem Solar Silicon (ESS®), and polysilicon - under full and selective parts of the light spectrum are presented based on results obtained using a AAA sun simulator. These results are of particular interest in understanding the possible causes behind the better temperature coefficients usually observed for ESS® compared to polysilicon solar cells when measured with a full AM1.5 spectrum. The optical filtered lights from four different regions of the spectrum have been used to examine the influence of temperature coefficients on the spectral composition. ESS® solar cells showed considerable…

Equilibrium coverage fluctuations: a new approach to quantify reversible adsorption of proteins.

2005

Cavités plasmoniques et nanosources optiques

2013

Optical microcavities exhibit high resonance quality, so that, they are of key interest for the design of low-threshold lasers or for achieving strong coupling regime. But, such systems support modes whose the volume remain diffraction limited.In this manuscript, we are interested in their plasmonic counterparts because they support confined modes at the sub-wavelength scale. First, we study an in-plane plasmonic cavity which is the transposition of 1D optical cavity to surface wave. We characterize the cavity by measuring the fluorescence lifetime of dye molecules deposited inside.Then, we are interested in 3-dimension mode confinement achieved by spherical metal nanoparticles. We discuss …

Study of the dynamics of biomolecules by high speed atomic force microscopy and surface enhanced Raman spectroscopy

2015

This thesis focuses on the coupling of High–Speed Atomic Force Microscopy (HS-AFM) and Surface Enhanced Raman Spectroscopy (SERS) for biomolecule analysis. We have designed a fabrication protocol to manufacture “SERS-active” substrates. The efficacy of gold, silver and gold-silver bimetallic crystalline nanoparticle substrates were evaluated. We have investigated the impact of optical and morphological features of the substrates on Raman signal intensity by analyzing well-known samples such as bipyridine ethylene and methylene blue molecules. We took an interest in three distinct biological problematics with HS-AFM and SERS analyses. First, we have detected the chemical signature of cytochr…

Optical near-field distributions of surface plasmon waveguide modes

2003

International audience; Thin gold stripes, featuring various widths in the micrometer range, were microfabricated to obtain surface-plasmon guides on a glass substrate. Each metal stripe (MS) was excited by an incident surface-plasmon polariton which was itself launched on an extended thin gold film by the total internal reflection of a focused beam coming through the substrate. The optical near-field distributions of the surface-plasmon (sp) modes sustained by the stripes were then recorded using a photon scanning tunneling microscope (PSTM). For a fixed frequency of the incident light, these field distributions are found to depend on the widths of the stripes. We first provide an experime…

Efficient thermo-optically controlled Mach-Zhender interferometers using dielectric-loaded plasmonic waveguides

2012

Compact fiber-coupled dielectric-loaded plasmonic Mach-Zehnder interferometers operating at telecom wavelengths and controlled via the thermo-optic effect are reported. Two fabricated structures with Cytop substrate and a ridge made of PMMA or a cycloaliphatic acrylate polymer (CAP) were considered showing low switching power of 2.35 mW and switching time in the range of microseconds for a CAP ridge and milliseconds switching time for a PMMA ridge. Full output modulation is demonstrated for the structure with a CAP ridge and 40% modulation with a PMMA ridge. (C) 2012 Optical Society of America Compact fiber-coupled dielectric-loaded plasmonic Mach-Zehnder interferometers operating at teleco…

Determination of the spatial extension of the surface-plasmon evanescent field of a silver film with a photon scanning tunneling microscope.

1993

A photon scanning tunneling microscope is employed to probe the surface-plasmon field in the evanes- cent region of a silver film for p (parallel to the plane of incidence) and s (perpendicular to the plane of incidence) polarizations of the light beam at several angles of incidence near the critical angle. The in- teraction between the field and the probe is measured and compared to theoretical calculations involving a single four-media model. A systematic analysis of images obtained for several positions of the optical fiber above the film is presented and it is shown that, for tip-to-sample distances smaller than half the wavelength of the incoming light, the collected intensity curves a…

A compound-based proteomic approach discloses 15-ketoatractyligenin methyl ester as a new PPARγ partial agonist with anti-proliferative ability

2017

AbstractProteomics based approaches are emerging as useful tools to identify the targets of bioactive compounds and elucidate their molecular mechanisms of action. Here, we applied a chemical proteomic strategy to identify the peroxisome proliferator-activated receptor γ (PPARγ) as a molecular target of the pro-apoptotic agent 15-ketoatractyligenin methyl ester (compound 1). We demonstrated that compound 1 interacts with PPARγ, forms a covalent bond with the thiol group of C285 and occupies the sub-pocket between helix H3 and the β-sheet of the ligand-binding domain (LBD) of the receptor by Surface Plasmon Resonance (SPR), mass spectrometry-based studies and docking experiments. 1 displayed…

Coupling colloidal chemistry with coordination chemistry: Design of hybrid nanomaterials by the assembly of plasmonic nanoparticles and functional co…

2021

Nanotechnology involves the design, characterization, production and application of structures, devices and systems by the control of the shape and size at the nanometer scale involving different fields. In the last decade, nanotechnology development has boosted the interest in hybrid nanomaterials. These materials are a complimenting combination of two (or more) nanoparticles (NPs) with enhanced performance characteristics that offer exciting opportunities. It allows the possibility of integrating materials with different physical and chemical properties to widen the range of practical applications. In this context, Au NPs have recently attracted a lot of attention due to the great opportu…