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Plasmonic propagations distances for interferometric surface plasmon resonance biosensing.

Lepage D, Carrier D, Jiménez A, Beauvais J, Dubowski JJ - Nanoscale Res Lett (2011)

Bottom Line: The result is an increased traceability of the SPR shifts for biosensing applications.The surface roughness and dielectric values for various deposition rates of very thin Au films are measured.We also investigate an interferometric SPR setup where, due to the power flux transfer between plasmon modes, the specific choice of grating coupler can either decrease or increase the plasmon propagation length.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Electrical and Computer Engineering, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada. Jan.J.Dubowski@USherbrooke.ca.

ABSTRACT
A surface plasmon resonance (SPR) scheme is proposed in which the local phase modulations of the coupled plasmons can interfere and yield phase-sensitive intensity modulations in the measured signal. The result is an increased traceability of the SPR shifts for biosensing applications. The main system limitation is the propagation distance of the coupled plasmon modes. This aspect is therefore studied for thin film microstructures operating in the visible and near-infrared spectral regions. The surface roughness of the substrate layer is examined for different dielectrics and deposition methods. The Au layer, on which the plasmonic modes are propagating and the biosensing occurs, is also examined. The surface roughness and dielectric values for various deposition rates of very thin Au films are measured. We also investigate an interferometric SPR setup where, due to the power flux transfer between plasmon modes, the specific choice of grating coupler can either decrease or increase the plasmon propagation length.

No MeSH data available.


Real and imaginary part of the 20-nm Au film at E = 1.4251 eV for various deposition rates. As the film compactness increases, the values tend towards bulk constants.
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Figure 6: Real and imaginary part of the 20-nm Au film at E = 1.4251 eV for various deposition rates. As the film compactness increases, the values tend towards bulk constants.

Mentions: Another fabrication aspect to take into account is the value of the dielectric constants of the films, especially those of the metal layer. These values were measured for various energies by ellipsometry for the thin Au films deposited at various rates. The results for E = 1.4271 eV are presented in Figure 6. As one can observe, both real and imaginary parts of the dielectric constant, εAu, are increasing with the deposition rate. This can be understood by analysing the AFM and SEM results showing that the film density increases with the deposition rate: thus, a higher value of the effective dielectric constant approaching that of the bulk material.


Plasmonic propagations distances for interferometric surface plasmon resonance biosensing.

Lepage D, Carrier D, Jiménez A, Beauvais J, Dubowski JJ - Nanoscale Res Lett (2011)

Real and imaginary part of the 20-nm Au film at E = 1.4251 eV for various deposition rates. As the film compactness increases, the values tend towards bulk constants.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211481&req=5

Figure 6: Real and imaginary part of the 20-nm Au film at E = 1.4251 eV for various deposition rates. As the film compactness increases, the values tend towards bulk constants.
Mentions: Another fabrication aspect to take into account is the value of the dielectric constants of the films, especially those of the metal layer. These values were measured for various energies by ellipsometry for the thin Au films deposited at various rates. The results for E = 1.4271 eV are presented in Figure 6. As one can observe, both real and imaginary parts of the dielectric constant, εAu, are increasing with the deposition rate. This can be understood by analysing the AFM and SEM results showing that the film density increases with the deposition rate: thus, a higher value of the effective dielectric constant approaching that of the bulk material.

Bottom Line: The result is an increased traceability of the SPR shifts for biosensing applications.The surface roughness and dielectric values for various deposition rates of very thin Au films are measured.We also investigate an interferometric SPR setup where, due to the power flux transfer between plasmon modes, the specific choice of grating coupler can either decrease or increase the plasmon propagation length.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Electrical and Computer Engineering, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada. Jan.J.Dubowski@USherbrooke.ca.

ABSTRACT
A surface plasmon resonance (SPR) scheme is proposed in which the local phase modulations of the coupled plasmons can interfere and yield phase-sensitive intensity modulations in the measured signal. The result is an increased traceability of the SPR shifts for biosensing applications. The main system limitation is the propagation distance of the coupled plasmon modes. This aspect is therefore studied for thin film microstructures operating in the visible and near-infrared spectral regions. The surface roughness of the substrate layer is examined for different dielectrics and deposition methods. The Au layer, on which the plasmonic modes are propagating and the biosensing occurs, is also examined. The surface roughness and dielectric values for various deposition rates of very thin Au films are measured. We also investigate an interferometric SPR setup where, due to the power flux transfer between plasmon modes, the specific choice of grating coupler can either decrease or increase the plasmon propagation length.

No MeSH data available.