TIP-ENHANCED NEAR-FIELD CARS MICROSCOPY

2004 ◽  
Vol 13 (03n04) ◽  
pp. 593-599 ◽  
Author(s):  
SATOSHI KAWATA ◽  
TARO ICHIMURA ◽  
NORIHIKO HAYAZAWA ◽  
YASUSHI INOUYE ◽  
MAMORU HASHIMOTO
Keyword(s):  
Spatial Resolution ◽  
Gold Film ◽  
Near Field ◽  
Field Enhancement ◽  
Single Wall Carbon Nanotubes ◽  
Enhancement Effect ◽  
Cars Microscopy ◽  
Plasmon Polariton ◽  
Anti Stokes ◽  
Cantilever Probe

We apply the field enhancement effect due to plasmon polariton excitation on a metallic nanostructure in order to improve the diffraction limited spatial resolution of coherent anti-Stokes Raman scattering (CARS) microscopy. A cantilever probe tip coated with a 25 nm-thick gold film is utilized as a near-field light source to locally excite the CARS polarizations near the tip. Our CARS microscope has effectively enhanced the CARS signals and realized vibrational imaging of single-wall carbon nanotubes (SWNTs) beyond the spatial resolution of far-field CARS microscopy.

scholarly journals Terminal Groups Dependent Near-Field Enhancement Effect of Ti3C2Tx Nanosheets

2020 ◽  
Author(s):  
Ying-Ying Yang ◽  
Wen-Tao Zhou ◽  
Wei-Long Song ◽  
Qing-Quan Zhu ◽  
Hao-Jiang Xiong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Oxidation Resistance ◽  
Functional Groups ◽  
Near Field ◽  
Field Enhancement ◽  
Electron Injection ◽  
Enhancement Effect ◽  
Hydroxyl Groups ◽  
Physical And Chemical

Abstract Both multilayered (ML) and few-layered (FL) Ti3C2Tx nanosheets with different dominant terminal groups have been prepared through a typical etching and delaminating procedure. Various characterizations confirm that the physical and chemical performance of the nanosheets are dependent on the dominant functional groups. It has been demonstrated that ML-Ti3C2Tx has been mainly terminated by O-related groups, which result in better oxidation resistance and stronger near-field enhancement effect. As for FL-Ti3C2Tx, which is mainly terminated by hydroxyl groups, it can be better dispersed in aqueous solution and could confine stronger near-field after coupling to Ag nanostructures by electron injection.

scholarly journals Terminal Groups-Dependent Near-Field Enhancement Effect of Ti3C2Tx Nanosheets

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ying-Ying Yang ◽  
Wen-Tao Zhou ◽  
Wei-Long Song ◽  
Qing-Quan Zhu ◽  
Hao-Jiang Xiong ◽  
...  
Keyword(s):  
Ag Nanoparticles ◽  
Near Field ◽  
Field Enhancement ◽  
Electron Injection ◽  
Hybrid Structure ◽  
Enhancement Effect ◽  
Hydroxyl Groups ◽  
Potential Applications ◽  
Physical And Chemical

AbstractBoth multilayered (ML) and few-layered (FL) Ti3C2Tx nanosheets have been prepared through a typical etching and delaminating procedure. Various characterizations confirm that the dominant terminal groups on ML-Ti3C2Tx and FL-Ti3C2Tx are different, which have been assigned to O-related and hydroxyl groups, respectively. Such deviation of the dominant terminals results in the different physical and chemical performance and eventually makes the nanosheets have different potential applications. In particular, before coupling to Ag nanoparticles, ML-Ti3C2Tx can present stronger near-field enhancement effect; however, Ag/FL-Ti3C2Tx hybrid structure can confine stronger near-field due to the electron injection, which can be offered by the terminated hydroxyl groups.

scholarly journals Synthesis of silver nanostructure on gold nanoparticle using near field assisted second harmonic generation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takashi Yatsui ◽  
Felix Brandenburg ◽  
Benjamin Leuschel ◽  
Olivier Soppera
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Absorption Edge ◽  
Second Harmonic ◽  
Near Field ◽  
Field Enhancement ◽  
Enhancement Effect ◽  
Field Source ◽  
Volume Increase ◽  
Silver Nanostructure

AbstractBy using gold (Au) nanoparticles (NPs) as an optical near-field source under far-field illumination in combination with a silver (Ag) ion solution containing a photoinitiator, we coated Ag on Au NPs using a near-field (NF)-assisted process. We evaluated the change in the size of the NPs using transmission electron microscopy. Evaluation of the synthesized Ag volume over illumination power confirmed the squared power dependence of the NP volume with illumination using 808 nm light, i.e., a wavelength longer than the absorption edge wavelength of the photoinitiator molecules. The rate of volume increase was much lower than the plasmonic field enhancement effect. Therefore, the squared power dependency of the volume increase using a wavelength longer than the absorption edge wavelength originated from NF-assisted second-harmonic generation and the resulting excitation.

scholarly journals Understanding the Role of Different Substrate Geometries for Achieving Optimum Tip-Enhanced Raman Scattering Sensitivity

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 376
Author(s):  
Lu He ◽  
Mahfujur Rahaman ◽  
Teresa I. Madeira ◽  
Dietrich R.T. Zahn
Keyword(s):  
Spatial Resolution ◽  
Near Field ◽  
Field Enhancement ◽  
Combined System ◽  
Gold Thin Film ◽  
Gold Nanostructure ◽  
Tip Enhanced Raman Spectroscopy ◽  
Metal Tip ◽  
20 Nm ◽  
Gap Mode

Tip-enhanced Raman spectroscopy (TERS) has experienced tremendous progress over the last two decades. Despite detecting single molecules and achieving sub-nanometer spatial resolution, attaining high TERS sensitivity is still a challenging task due to low reproducibility of tip fabrication, especially regarding very sharp tip apices. Here, we present an approach for achieving strong TERS sensitivity via a systematic study of the near-field enhancement properties in the so-called gap-mode TERS configurations using the combination of finite element method (FEM) simulations and TERS experiments. In the simulation study, a gold tip apex is fixed at 80 nm of diameter, and the substrate consists of 20 nm high gold nanodiscs with diameter varying from 5 nm to 120 nm placed on a flat extended gold substrate. The local electric field distributions are computed in the spectral range from 500 nm to 800 nm with the tip placed both at the center and the edge of the gold nanostructure. The model is then compared with the typical gap-mode TERS configuration, in which a tip of varying diameter from 2 nm to 160 nm is placed in the proximity of a gold thin film. Our simulations show that the tip-nanodisc combined system provides much improved TERS sensitivity compared to the conventional gap-mode TERS configuration. We find that for the same tip diameter, the spatial resolution achieved in the tip-nanodisc model is much better than that observed in the conventional gap-mode TERS, which requires a very sharp metal tip to achieve the same spatial resolution on an extended metal substrate. Finally, TERS experiments are conducted on gold nanodisc arrays using home-built gold tips to validate our simulation results. Our simulations provide a guide for designing and realization of both high-spatial resolution and strong TERS intensity in future TERS experiments.

scholarly journals Near-field optics for nanoprocessing

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Mitsuhiro Terakawa ◽  
Nikolay N. Nedyalkov
Keyword(s):  
Laser Processing ◽  
Recent Progress ◽  
Coupling Effect ◽  
Near Field ◽  
Field Enhancement ◽  
Mie Scattering ◽  
Diffraction Limit ◽  
Near Field Optics ◽  
Potential Applications ◽  
Plasmon Polariton

AbstractThe recent progress in laser processing reaches a level where a precise fabrication that overcomes the diffraction limit of the far-field optics can be achieved. Laser processing mediated by enhanced near field is one of the attractive methods to provide highly precise structuring with a simple apparatus. In this review, we describe the fundamentals of the electromagnetic near field in the vicinity of small structures and the application of its specific properties for nanomodification. Theoretical and experimental results on nanoablation based on electromagnetic field enhancement due to plasmon polariton excitation and Mie scattering are discussed. High-throughput nanohole fabrication mediated by arrayed nanospheres is discussed, as the coupling effect of near field is also considered. In addition, recent fabrication techniques and their potential applications in nanopatterning, nanoscale deformation, and biophotonics are discussed.

scholarly journals Electromagnetic Field Enhancement of Nanostructured TiN Electrodes Probed with Surface-Enhanced Raman Spectroscopy

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 487
Author(s):  
Ibrahim Halil Öner ◽  
Christin David ◽  
Christine Joy Querebillo ◽  
Inez M. Weidinger ◽  
Khoa Hoang Ly
Keyword(s):  
Electromagnetic Field ◽  
Near Field ◽  
Field Enhancement ◽  
Surface Enhanced Raman Spectroscopy ◽  
Enhancement Effect ◽  
Surface Binding ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Optical Region ◽  
Rigorous Coupled Wave

We present a facile approach for the determination of the electromagnetic field enhancement of nanostructured TiN electrodes. As model system, TiN with partially collapsed nanotube structure obtained from nitridation of TiO2 nanotube arrays was used. Using surface-enhanced Raman scattering (SERS) spectroscopy, the electromagnetic field enhancement factors (EFs) of the substrate across the optical region were determined. The non-surface binding SERS reporter group azidobenzene was chosen, for which contributions from the chemical enhancement effect can be minimized. Derived EFs correlated with the electronic absorption profile and reached 3.9 at 786 nm excitation. Near-field enhancement and far-field absorption simulated with rigorous coupled wave analysis showed good agreement with the experimental observations. The major optical activity of TiN was concluded to originate from collective localized plasmonic modes at ca. 700 nm arising from the specific nanostructure.

scholarly journals Distinguishable Plasmonic Nanoparticle and Gap Mode Properties in a Silver Nanoparticle on a Gold Film System Using Three-Dimensional FDTD Simulations

Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 582 ◽  
Author(s):  
Vasanthan Devaraj ◽  
Jong-Min Lee ◽  
Jin-Woo Oh
Keyword(s):  
Layer Thickness ◽  
Silver Nanoparticle ◽  
Dielectric Layer ◽  
Gold Film ◽  
Computational Study ◽  
Near Field ◽  
Three Dimensional ◽  
Field Enhancement ◽  
Plasmonic Nanoparticle ◽  
Gap Mode

We present a computational study of the near-field enhancement properties from a plasmonic nanomaterial based on a silver nanoparticle on a gold film. Our simulation studies show a clear distinguishability between nanoparticle mode and gap mode as a function of dielectric layer thickness. The observed nanoparticle mode is independent of dielectric layer thickness, and hence its related plasmonic properties can be investigated clearly by having a minimum of ~10-nm-thick dielectric layer on a metallic film. In case of the gap mode, the presence of minimal dielectric layer thickness is crucial (~≤4 nm), as deterioration starts rapidly thereafter. The proposed simple tunable gap-based particle on film design might open interesting studies in the field of plasmonics, extreme light confinement, sensing, and source enhancement of an emitter.

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