Abstract Optical responses in dilute composites are controlled through the local dielectric resonance of metallic clusters. We consider two located metallic clusters close to each other with admittances $\varepsilon$1 and $\varepsilon$2. Through varying the difference admittance ratio $\eta [ = (\varepsilon _2 - \varepsilon_0 ) / (\varepsilon _1 - \varepsilon _0 )]$, we find that their optical responses are determined by the local resonance. There is a blueshift of absorption peaks with the increase of $\eta$. Simultaneously, it is known that the absorption peaks will be redshifted by enlarging the cluster size. By adjusting the nano-metallic cluster geometry, size and admittances, we can control the positions and intensities of absorption peaks effectively. We have also deduced the effective linear optical responses of three-component composites $\varepsilon _{\rm e} = \varepsilon _0\bigl(1 + \sum_{n = 1}^{n_{\rm s} } [({{\gamma _{n_1 } + \eta \gamma_{n_2 } })/({\varepsilon _0 (s - s_{n} )})]} \bigr)$, and the sum rule of cross sections: $\sum_{n = 1}^{n_{\rm s} } {(\gamma _{n_1 } +\eta \gamma _{n_2 } ) = N_{h_1 } + N_{h_2 } } $, where $N_{h_1}$ and $N_{h_2}$ are the numbers of $\varepsilon _1 $ and $\varepsilon _2$ bonds along the electric field, respectively. These results may be beneficial to the study of surface plasmon resonances on a nanometre scale.
Received: 02 June 2006
Revised: 02 August 2006
Accepted manuscript online:
PACS:
61.46.Bc
(Structure of clusters (e.g., metcars; not fragments of crystals; free or loosely aggregated or loosely attached to a substrate))
(Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures)
Fund: Project supported by the
National Natural Science Foundation of China(Grant Nos 10304001,
10334010, 10521002, 10434020, 10328407 and 90501007).
Cite this article:
Chen Liang-Liang(陈亮亮), Gu Ying(古英), Wang Li-Jin(王立金), and Gong Qi-Huang(龚旗煌) Controlling optical responses through local dielectric resonance in nanometre metallic clusters 2007 Chinese Physics 16 249
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.