Please use this identifier to cite or link to this item:
|Title:||Plasmonic nanoclusters with rotational symmetry: Polarization-invariant far-field response vs changing near-field distribution|
|Keywords:||near-field optical microscopy|
|Citation:||Rahmani, M., Yoxall, E., Hopkins, B., Sonnefraud, Y., Kivshar, Y., Hong, M., Phillips, C., Maier, S.A., Miroshnichenko, A.E. (2013-12-23). Plasmonic nanoclusters with rotational symmetry: Polarization-invariant far-field response vs changing near-field distribution. ACS Nano 7 (12) : 11138-11146. ScholarBank@NUS Repository. https://doi.org/10.1021/nn404869c|
|Abstract:||Flexible control over the near- and far-field properties of plasmonic nanostructures is important for many potential applications, such as surface-enhanced Raman scattering and biosensing. Generally, any change in the polarization of the incident light leads to a change in the nanoparticle's near-field distribution and, consequently, in its far-field properties as well. Therefore, producing polarization-invariant optical responses in the far field from a changing near field remains a challenging issue. In this paper, we probe experimentally the optical properties of cruciform pentamer structures - as an example of plasmonic oligomers - and demonstrate that they exhibit such behavior due to their symmetric geometrical arrangement. We demonstrate direct control over hot spot positions in sub-20 nm gaps, between disks of 145 nm diameter at a wavelength of 850 nm, by means of scattering scanning near-field optical microscopy. In addition, we employ the coupled dipole approximation method to define a qualitative model revealing the relationship between the near and far field in such structures. The near-field profiles depend on particular mode superpositions excited by the incident field and, thus, are expected to vary with the polarization. Consequently, we prove analytically that the far-field optical properties of pentamers have to be polarization-independent due to their rotational symmetry. © 2013 American Chemical Society.|
|Source Title:||ACS Nano|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Jul 14, 2018
WEB OF SCIENCETM
checked on Jul 4, 2018
checked on Jul 6, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.