| 1. |
- Alaverdyan, Yury, 1976, et al.
(författare)
-
Optical antennas based on coupled nanoholes in thin metal films
- 2007
-
Ingår i: Nature Physics. - : Springer Science and Business Media LLC. - 1745-2481 .- 1745-2473. ; 3:12, s. 884-889
-
Tidskriftsartikel (refereegranskat)abstract
- The ability to control optical effects at the nanoscale is a challenge that could be of great importance for a range of photonic applications. However, progress requires a deep understanding of the relationship between near-field and far-field properties of the individual elements of the nanostructure, as well as of the role of nano-optical interactions. Here, we show that the strong interaction between nanoholes in optically thin metal films can be used to readily tune their spectral response and visibility. Control of this interaction in short chains of nanoholes enables either amplification or almost total suppression of the scattered light. The phenomena are interpreted in terms of hole coupling mediated via antisymmetric surface plasmon polaritons, which makes the nanohole chains effectively behave as linear wire antennas.
|
|
| 2. |
- Brian, Björn, 1980, et al.
(författare)
-
Sensitivity enhancement of nanoplasmonic sensors on low refractive index substrates
- 2009
-
Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 17:3, s. 2015-2023
-
Tidskriftsartikel (refereegranskat)abstract
- Metal films perforated by nanoholes constitute a powerful platform for surface plasmon resonance biosensing. We find that the refractive index sensitivity of nanohole arrays increases if their resonance is red-shifted by increasing the separation distance between holes. However, an additional sensitivity enhancement occurs if the nanohole sensors are manufactured on low index substrates, despite the fact such substrates significantly blue-shift the resonance. We find a ∼40% higher bulk refractive index sensitivity for a system of -100 nm holes in 20 nm gold films fabricated on Teflon substrates (n=1.32) compared to the case when conventional glass substrates (n=1.52) are used. A similar improvement is observed for the case when a thin layer of dielectric material is deposited on the samples. These results can be understood by considering the electric field distribution induced by the so-called antisymmetric surface plasmon polariton in the thin gold films.
|
|
| 3. |
- Gonzalez-Diaz, J. B., et al.
(författare)
-
Plasmonic Au/Co/Au nanosandwiches with enhanced magneto-optical activity
- 2008
-
Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 4:2, s. 202-205
-
Tidskriftsartikel (refereegranskat)abstract
- A study was conducted to analyzed magneto-optical (MO) activity of thin films prepared by Au/Co/Au trilayers as surface plasmon polaritons. Trilyers exhibit a magnetic-field-induced nonreciprocal effect in the surface plasmon polariton propagation. The Au/Co/Au nanosandwiches, prepared by a self-assembly process, show localized surface plasmon resonances (LSPRs) that affect the optical properties of metallic nanostructures. The fabrication of the nanostructures was performed using colloidal lithography (CL). An atomic force microscopy was used to analyze the structure of thin films. The polar Kerr ellipticity and rotation spectra for an array of nanoparticles with identical dimensions were examined. Metal trilyer films were sputtered onto glass substrates. Results show that nanoparticles can be used for the development of high-sensitive magnetoplasmonic nanosensors with multiplexing capabilities.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Alegret, Joan, 1977, et al.
(författare)
-
Plasmonic properties of silver trimers with trigonal symmetry fabricated by electron-beam lithography
- 2008
-
Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 112:37, s. 14313-14317
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate the dipolar plasmon modes of nanoparticle trimers formed by three equal silver disks of diameter D = 100 nm located on the vertexes of an equilateral triangle. Samples were fabricated by electron-beam lithography and studied experimentally by dark-field spectroscopy. The results are found to be in good agreement with electrodynamical simulations based on the discrete dipole approximation (DDA). Similar to nanoparticle dimers, the trimer system exhibits two hybridized dipole resonances to the red and to the blue of the single particle resonance. However, the far-field spectra are polarization-insensitive for light incident normal to the plane of the trimer, and the peak shifts, which occur as the edge-to-edge distance d between the particles decrease, are smaller than for dimers. Moreover, we find that the dipolar displacement patterns are well described by linear combinations of bonding and antibonding symmetry adapted coordinates obtained through symmetry analysis based on the ideal D-3h point-group.
|
|
| 8. |
|
|
| 9. |
- Fredriksson, Hans, 1974, et al.
(författare)
-
Hole-Mask Colloidal Lithography
- 2007
-
Ingår i: Advanced Materials. ; 19, s. 4297-4302
-
Tidskriftsartikel (refereegranskat)
|
|
| 10. |
- Hartling, T., et al.
(författare)
-
Optically controlled interparticle distance tuning and welding of single gold nanoparticle pairs by photochemical metal deposition
- 2008
-
Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 16:16, s. 12362-12371
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the in-situ controlled tuning of the particle gap in single pairs of gold nanodisks by photochemical metal deposition. The optically induced growth of nanodisk dimers fabricated by electron beam lithography leads to a decrease of the interparticle gap width down to 0 nm. Due to the increasing particle size and stronger plasmonic coupling, a smooth redshift of the localized surface plasmon (LSP) resonances is observed in such particle pairs during the growth process. The interparticle gap width, and hence the LSP resonance, can be tuned to any desired spectral position. The experimental results we obtain with this nanoscale fabrication technique are well described by the so-called plasmon ruler equation. Consequently, both the changes in particle diameter as well as in gap width can be characterized in-situ via far-field read-out of the optical properties of the dimers.
|
|
