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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.


Related in: MedlinePlus

SPR Interferometer; (a) Interference of adjacent SP modes; the incident coherent wave couples SP modes on both finite gratings. The probing SP (A) propagates across the cavity and recombines with the reference SP (B), thus forming the combined SP mode (A + B). As the optical path length of the cavity is increased by the presence of biomolecular agents on the surface, the probing SP is phase delayed and the resulting interference pattern will be modified, cycling from constructive to destructive interferences. (b) Conceptualization of the system, where an incident light (Io) hits a grating pair. The light intensity is then distributed between the transmission (To), the reflection (Ro), the coupled SPR (MSP) and some constant absorption. As MSP is modulated by the phase shift induced by the cavity, monitoring Ro or To can reveal information on the interference conditions of A + B.
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Figure 1: SPR Interferometer; (a) Interference of adjacent SP modes; the incident coherent wave couples SP modes on both finite gratings. The probing SP (A) propagates across the cavity and recombines with the reference SP (B), thus forming the combined SP mode (A + B). As the optical path length of the cavity is increased by the presence of biomolecular agents on the surface, the probing SP is phase delayed and the resulting interference pattern will be modified, cycling from constructive to destructive interferences. (b) Conceptualization of the system, where an incident light (Io) hits a grating pair. The light intensity is then distributed between the transmission (To), the reflection (Ro), the coupled SPR (MSP) and some constant absorption. As MSP is modulated by the phase shift induced by the cavity, monitoring Ro or To can reveal information on the interference conditions of A + B.

Mentions: The basic principle of the SPR interferometry is schematised in Figure 1, where a single coherent beam is used to excite SP modes through spatially localized finite gratings distributed evenly on the metal-dielectric architecture. Those SP modes propagate outwards of the finite grating regions into the cavity regions, where they are phase delayed by an overlying biomolecular environment, before they interfere with the neighbouring SP modes. In a reflection-based SPR experiment, modulations in the reflection (Ro) deliver the information about the SPs interference. In the case of transmission-based SPR, where the illumination source is embedded in the device [3], the transmission (To) would be monitored.


Plasmonic propagations distances for interferometric surface plasmon resonance biosensing.

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

SPR Interferometer; (a) Interference of adjacent SP modes; the incident coherent wave couples SP modes on both finite gratings. The probing SP (A) propagates across the cavity and recombines with the reference SP (B), thus forming the combined SP mode (A + B). As the optical path length of the cavity is increased by the presence of biomolecular agents on the surface, the probing SP is phase delayed and the resulting interference pattern will be modified, cycling from constructive to destructive interferences. (b) Conceptualization of the system, where an incident light (Io) hits a grating pair. The light intensity is then distributed between the transmission (To), the reflection (Ro), the coupled SPR (MSP) and some constant absorption. As MSP is modulated by the phase shift induced by the cavity, monitoring Ro or To can reveal information on the interference conditions of A + B.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: SPR Interferometer; (a) Interference of adjacent SP modes; the incident coherent wave couples SP modes on both finite gratings. The probing SP (A) propagates across the cavity and recombines with the reference SP (B), thus forming the combined SP mode (A + B). As the optical path length of the cavity is increased by the presence of biomolecular agents on the surface, the probing SP is phase delayed and the resulting interference pattern will be modified, cycling from constructive to destructive interferences. (b) Conceptualization of the system, where an incident light (Io) hits a grating pair. The light intensity is then distributed between the transmission (To), the reflection (Ro), the coupled SPR (MSP) and some constant absorption. As MSP is modulated by the phase shift induced by the cavity, monitoring Ro or To can reveal information on the interference conditions of A + B.
Mentions: The basic principle of the SPR interferometry is schematised in Figure 1, where a single coherent beam is used to excite SP modes through spatially localized finite gratings distributed evenly on the metal-dielectric architecture. Those SP modes propagate outwards of the finite grating regions into the cavity regions, where they are phase delayed by an overlying biomolecular environment, before they interfere with the neighbouring SP modes. In a reflection-based SPR experiment, modulations in the reflection (Ro) deliver the information about the SPs interference. In the case of transmission-based SPR, where the illumination source is embedded in the device [3], the transmission (To) would be monitored.

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.


Related in: MedlinePlus