Electrochemical THz-SERS Observation of Thiol Monolayers on Au(111) and (100) Using Nanoparticle-assisted Gap-Mode Plasmon Excitation

2017 ◽  
Vol 8 (17) ◽  
pp. 4236-4240 ◽  
Author(s):  
Motoharu Inagaki ◽  
Kenta Motobayashi ◽  
Katsuyoshi Ikeda
Keyword(s):  
Plasmon Excitation ◽  
Thiol Monolayers ◽  
Gap Mode

STEM Study of Surface Plasmon Excitation in Small Spherical Particles

1990 ◽  
Vol 48 (2) ◽  
pp. 42-43
Author(s):  
Daniel UGARTE
Keyword(s):  
Energy Loss ◽  
Spherical Particles ◽  
Small Particles ◽  
Bulk Materials ◽  
Low Loss ◽  
Plasmon Excitation ◽  
Surface Modes ◽  
Surface Plasmon Excitation ◽  
Analytical Electron ◽  
Analytical Electron Microscope

Small particles exhibit chemical and physical behaviors substantially different from bulk materials. This is due to the fact that boundary conditions can induce specific constraints on the observed properties. As an example, energy loss experiments carried out in an analytical electron microscope, constitute a powerful technique to investigate the excitation of collective surface modes (plasmons), which are modified in a limited size medium. In this work a STEM VG HB501 has been used to study the low energy loss spectrum (1-40 eV) of silicon spherical particles [1], and the spatial localization of the different modes has been analyzed through digitally acquired energy filtered images. This material and its oxides have been extensively studied and are very well characterized, because of their applications in microelectronics. These particles are thus ideal objects to test the validity of theories developed up to now.Typical EELS spectra in the low loss region are shown in fig. 2 and energy filtered images for the main spectral features in fig. 3.

Investigation of cluster layers of small netal particles by TEM, SEM, EELS and by photoacoustic spectroscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 250-251
Author(s):  
H. Seiler ◽  
U. Haas ◽  
K.H. Körtje
Keyword(s):  
Bulk Material ◽  
High Vacuum ◽  
Optical Methods ◽  
Metal Particles ◽  
Silver Particles ◽  
Low Loss ◽  
Plasmon Excitation ◽  
First Results ◽  
Diffraction Patterns ◽  
Small Metal Particles

The physical properties of small metal particles reveal an intermediate position between atomic and bulk material. Especially Ag has shown pronounced size effects. We compared silver layers evaporated in high vacuum with cluster layers of small silver particles, evaporated in N2 at a pressure of about 102 Pa. The investigations were performed by electron optical methods (TEM, SEM, EELS) and by Photoacoustic (PA) Spectroscopy (gas-microphone detection).The observation of cluster layers with TEM and high resolution SEM show small silver particles with diameters of about 50 nm (Fig. 1 and Figure 2, respectively). The electron diffraction patterns of homogeneous Ag layers and of cluster layers are similar, whereas the low loss EELS spectra due to plasmon excitation are quite different. Fig. 3 and Figure 4 show first results of EELS spectra of a cluster layer of small silver particles on carbon foil and of a homogeneous Ag layer, respectively.

Enhanced Photocurrent Properties of Dye/Au-Loaded TiO2 Films by Grating-Coupled Surface Plasmon Excitation

2013 ◽  
Vol E96.C (3) ◽  
pp. 385-388 ◽  
Author(s):  
Hathaithip NINSONTI ◽  
Weerasak CHOMKITICHAI ◽  
Akira BABA ◽  
Wiyong KANGWANSUPAMONKON ◽  
Sukon PHANICHPHANT ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Tio2 Films ◽  
Plasmon Excitation ◽  
Surface Plasmon Excitation

Optical Properties of Sputtered Silver Granular Films

2005 ◽  
Vol 480-481 ◽  
pp. 287-292 ◽  
Author(s):  
S.E. Paje ◽  
F. Teran ◽  
J.M. Riveiro ◽  
J. Llopis ◽  
M.A. García ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Optical Properties ◽  
Optical Absorption ◽  
Surface Morphology ◽  
Silver Clusters ◽  
Plasmon Excitation ◽  
Granular Films ◽  
Silver Films ◽  
Atomic Force ◽  
Atomic Force Micrographs

In this research we study optical absorption and morphology of silver films prepared with a sputtering method. Silver granular films are obtained on a glass substrate for films with thickness smaller than about 60 Å. Superficial silver clusters of around 100 nm in diameter are clearly seen in the atomic force micrographs. The absorption of these samples are characterized by plasmon excitation in the 450-650 nm spectral range, which differs from the known excitation of silver nanoparticles fabricated by different techniques. The optical absorption of silver granular films depend on sputtering conditions like substrate temperature or deposition rate and correlates with the surface morphology.

scholarly journals Generation of terahertz vector beams using dielectric metasurfaces via spin-decoupled phase control

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3393-3402 ◽  
Author(s):  
Yuehong Xu ◽  
Huifang Zhang ◽  
Quan Li ◽  
Xueqian Zhang ◽  
Quan Xu ◽  
...  
Keyword(s):  
High Performance ◽  
Special Kind ◽  
Phase Control ◽  
High Resolution Imaging ◽  
Plasmon Excitation ◽  
Bessel Beams ◽  
Dynamic Phase ◽  
Vector Beams ◽  
Resolution Imaging ◽  
Spatially Variant

AbstractCylindrical vector beams (CVBs), being a special kind of beams with spatially variant states of polarizations, are promising in photonics applications, including high-resolution imaging, plasmon excitation, optical trapping, and laser machining. Recently, generating CVBs using metasurfaces has drawn enormous interest owing to their highly designable, multifunctional, and integratable features. However, related studies remain unexplored in the terahertz regime. Here, a generic method for efficiently generating terahertz CVBs carrying orbital angular momentums (OAMs) is proposed and experimentally demonstrated using transmission-type spatial-variant dielectric metasurfaces, which is realized by designing the interference between the two circularly polarized transmission components. This method is based on spin-decoupled phase control allowed by simultaneously manipulating the dynamic phase and geometric phase of each structure, endowing more degree of freedom in designing the vector beams. Two types of metasurfaces which respectively generate polarization-dependent terahertz vector vortex beams (VVBs) and vector Bessel beams (VBBs) are experimentally characterized. The proposed method opens a new window to generate versatile vector beams, providing new capabilities in developing novel, compact, and high-performance devices applicable to broad electromagnetic spectral regimes.

scholarly journals Directional Plasmonic Excitation by Helical Nanotips

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1333
Author(s):  
Leeju Singh ◽  
Nicolò Maccaferri ◽  
Denis Garoli ◽  
Yuri Gorodetski
Keyword(s):  
Surface Plasmon ◽  
Single Scattering ◽  
Coupling Factor ◽  
Metallic Surface ◽  
Phase Matching ◽  
Plasmon Excitation ◽  
Surface Plasmon Excitation ◽  
Specific Momentum ◽  
Plasmon Polaritons ◽  
Strong Spin

The phenomenon of coupling between light and surface plasmon polaritons requires specific momentum matching conditions. In the case of a single scattering object on a metallic surface, such as a nanoparticle or a nanohole, the coupling between a broadband effect, i.e., scattering, and a discrete one, such as surface plasmon excitation, leads to Fano-like resonance lineshapes. The necessary phase matching requirements can be used to engineer the light–plasmon coupling and to achieve a directional plasmonic excitation. Here, we investigate this effect by using a chiral nanotip to excite surface plasmons with a strong spin-dependent azimuthal variation. This effect can be described by a Fano-like interference with a complex coupling factor that can be modified thanks to a symmetry breaking of the nanostructure.

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