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Multiple metallic-shell nanocylinders for surface-enhanced spectroscopes.

Lu JY, Chiu KP, Chao HY, Chang YH - Nanoscale Res Lett (2011)

Bottom Line: The resonance wavelength and local field enhancement of this plasmon mode can be tuned by varying the pair-distance between the pairs, the gap-distance between the pairs, and the optical constants of the dielectric-core and the surrounding medium.The results show that the multiple core-shell nanocylinder pair contains the plasmon mode same as that of the solid metallic cylinder pairs at the long wavelength part of the spectrum.The large electric field intensity in the infrared region at long wavelength makes multiple core-shell cylinders as ideal candidates for surface-enhanced spectroscopes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, National Taiwan University, Taiwan. yuanhuei@ntu.edu.tw.

ABSTRACT
The optical properties of multiple dielectric-core-gold-shell nanocylinder pairs are investigated by two-dimensional finite difference time domain method. The core-shell cylinders are assumed to be of the same dimension and composition. For normal incidence, the diffraction spectra of multiple cylinder pairs contain the lightning-rod plasmon mode, and the electric field intensity is concentrated in the gap between the nanocylinder pairs in the infrared region. The resonance wavelength and local field enhancement of this plasmon mode can be tuned by varying the pair-distance between the pairs, the gap-distance between the pairs, and the optical constants of the dielectric-core and the surrounding medium. The results show that the multiple core-shell nanocylinder pair contains the plasmon mode same as that of the solid metallic cylinder pairs at the long wavelength part of the spectrum. The large electric field intensity in the infrared region at long wavelength makes multiple core-shell cylinders as ideal candidates for surface-enhanced spectroscopes.

No MeSH data available.


The normalized electric field intensity at the respective coupling plasmon modes wavelength of two silica-core gold-shell nanocylinder with the same geometry shown in Figure 2.
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Figure 3: The normalized electric field intensity at the respective coupling plasmon modes wavelength of two silica-core gold-shell nanocylinder with the same geometry shown in Figure 2.

Mentions: In addition, it is found that one of the plasmon modes is excited at much longer wavelengths. The electric field distribution shows that this mode is the result of the interaction between the electrons at the outer surface of the four nanocylinders. The normalized electric field intensity is investigated by propagating a plane wave at the respective plasmon modes of two dielectric-core-gold-shell nanocylinder pairs with the same geometry as shown in Figure 3. It is found that the electric field intensity decreases inside the dielectric core of the nanocylinder when the incident wavelength increases. This is due to the metal screening effect because the skin depth of gold increases when the wavelength of incident wave decreases.


Multiple metallic-shell nanocylinders for surface-enhanced spectroscopes.

Lu JY, Chiu KP, Chao HY, Chang YH - Nanoscale Res Lett (2011)

The normalized electric field intensity at the respective coupling plasmon modes wavelength of two silica-core gold-shell nanocylinder with the same geometry shown in Figure 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211226&req=5

Figure 3: The normalized electric field intensity at the respective coupling plasmon modes wavelength of two silica-core gold-shell nanocylinder with the same geometry shown in Figure 2.
Mentions: In addition, it is found that one of the plasmon modes is excited at much longer wavelengths. The electric field distribution shows that this mode is the result of the interaction between the electrons at the outer surface of the four nanocylinders. The normalized electric field intensity is investigated by propagating a plane wave at the respective plasmon modes of two dielectric-core-gold-shell nanocylinder pairs with the same geometry as shown in Figure 3. It is found that the electric field intensity decreases inside the dielectric core of the nanocylinder when the incident wavelength increases. This is due to the metal screening effect because the skin depth of gold increases when the wavelength of incident wave decreases.

Bottom Line: The resonance wavelength and local field enhancement of this plasmon mode can be tuned by varying the pair-distance between the pairs, the gap-distance between the pairs, and the optical constants of the dielectric-core and the surrounding medium.The results show that the multiple core-shell nanocylinder pair contains the plasmon mode same as that of the solid metallic cylinder pairs at the long wavelength part of the spectrum.The large electric field intensity in the infrared region at long wavelength makes multiple core-shell cylinders as ideal candidates for surface-enhanced spectroscopes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, National Taiwan University, Taiwan. yuanhuei@ntu.edu.tw.

ABSTRACT
The optical properties of multiple dielectric-core-gold-shell nanocylinder pairs are investigated by two-dimensional finite difference time domain method. The core-shell cylinders are assumed to be of the same dimension and composition. For normal incidence, the diffraction spectra of multiple cylinder pairs contain the lightning-rod plasmon mode, and the electric field intensity is concentrated in the gap between the nanocylinder pairs in the infrared region. The resonance wavelength and local field enhancement of this plasmon mode can be tuned by varying the pair-distance between the pairs, the gap-distance between the pairs, and the optical constants of the dielectric-core and the surrounding medium. The results show that the multiple core-shell nanocylinder pair contains the plasmon mode same as that of the solid metallic cylinder pairs at the long wavelength part of the spectrum. The large electric field intensity in the infrared region at long wavelength makes multiple core-shell cylinders as ideal candidates for surface-enhanced spectroscopes.

No MeSH data available.