Search results for "plasmon"

Direct observation of localized surface plasmon coupling

1999

We report on the direct observation of localized surface plasmon coupling using a photon scanning tunneling microscope. The surface plasmons are excited in gold nanostructures tailored by electron beam lithography. Electromagnetic energy transfer from a resonantly excited nanoparticle to a nanowire, which is not directly excited by the incident light is observed. Our experimental results appear to be in good agreement with theoretical computations based on Green's dyadic technique.

Local excitation of surface plasmon polaritons at discontinuities of a metal film: Theoretical analysis and optical near-field measurements

2002

Nonresonant excitation of surface plasmon polaritons at discontinuities of a gold film is numerically studied and experimentally observed with scanning near-field optical microscopy. It is shown that surface polaritons can be effectively launched at the edges of a metal film illuminated at an angle of incidence greater than the resonant angle of surface polariton excitation. The electromagnetic near-field distribution over a thin metal film exhibits significantly different features under resonant and nonresonant excitations due to different surface polariton excitation mechanisms. In the latter case the field distribution is determined by the interference of the excitation light and surface…

Controlling Light Confinement by Excitation of Localized Surface Plasmons

2007

Localized surface plasmons can be used to control near-field optical phenomena in the subwavelength range. Specifically, this chaper reviews recent results which show that localized surface plasmons can confine the optical intensity down to nanoscopic dimensions. The discussion first considers how a collection-mode near-field optical microscope can observe the squeezing of the plasmon field of metallic nanostructures deposited on a flat surface. Numerical simulations then provide illustrations of the confined fields associated with nanostructures which are feasible using current microfabrication techniques. Finally, we present arguments which explain how localized surface plasmons can deliv…

Mapping surface plasmon propagation by collection-mode near-field microscopy

2011

Surface plasmon propagation along striped Gold structures has been investigated by collection-mode near-field microscopy, leading to map the field intensity at the structure surface and to assess the system behavior at the nanoscale.

Chapter 3 Surface Plasmon Optics for the Characterization of Biofunctional Architectures

2007

Publisher Summary This chapter describes a wide variety of work employing surface plasmon resonance (SPR), surface plasmon field-enhanced fluorescence spectroscopy (SPFS), and surface plasmon field-enhanced diffraction spectroscopy (SPDS) analysis, specifically for investigations relevant to biofunctional, bio-affinity aspects. The SPR has shown already its impact on interfacial analysis. The combination of these three methods has the potential to generate more information and reveal details of biofunctional interfaces. The versatility of the SPR technique is shown by a vast amount of publications in the past decades; the method has matured into a well-accepted analytical tool for the chara…

NEAR-FIELD OPTICAL EXCITATION AND DETECTION OF SURFACE PLASMONS

2007

Characterization of thermo-optical 2×2 switch configurations made of Dielectric Loaded Surface Plasmon Polariton Waveguides for telecom routing archi…

2012

We report on the characterization of thermo-optic switch structures based on Dielectric Loaded Surface Plasmon Polariton Waveguide for high data bit rate transfer. Performances are extracted by Leakage Radiation Microscopy and compared to numerical results.

Thermally induced emission of light from a metallic diffraction grating, mediated by surface plasmons

1999

The angular emission of light of wavelength 710 and 810 nm from a gold diffraction grating was studied at about 700°C. A peak in the emission was found for defined angles. This contribution is purely TM-polarised and is attributed to thermally excited surface plasmons, coupled to light waves by the diffraction grating.

Curvature effects in surface plasmon dispersion and coupling

2005

We have studied the resonant coupling of surface plasmons in curved thin-film tunneling geometries by obtaining the dispersion relations for the system. The surface plasmon dispersion relations are calculated for a metal-coated dielectric probe above a dielectric half space with and without metal coating. The system is modeled in the prolate spheroidal system, and the dispersion relations are studied as functions of the parameter that defines the boundaries of the tip and the corresponding coating, and as functions of the involved coating thicknesses. Using this type of probe-substrate configuration, the nonradiative surface plasmon coupling mechanism is investigated in the visible spectrum…

Differential method for modeling dielectric-loaded surface plasmon polariton waveguides

2008

This paper demonstrates the efficiency of the differential method, a conventional grating theory, to investigate dielectric loaded surface plasmon polariton waveguides (DLSPPWs), known to be a potential solution for optical interconnects. The method is used to obtain the mode effective indices (both real and imaginary parts) and the mode profiles. The results obtained with the differential method are found to be in good agreement with those provided by the effective index method or finite elements. The versatility of the differential method is demonstrated by considering complex configurations such as trapezoidal waveguides or DLSPPWs lying on a finite width metal stripe.