THESIS
2019
xvi, 95 pages : illustrations (chiefly color) ; 30 cm
Abstract
Surface plasmon resonance (SPR) has found wide applications in sensing down to molecular
level due to its extreme sensitivity to change of dielectric properties. An unavoidable effect in SPR
is surface deformation (thermal bump) due to local heating by incident laser light used in SPR
excitation. In addition, the change in reflection phase from an SPR-supported metal film could
also contribute to the SPR signal variation, and thus proper handling of measured SPR signals is
very important in order to broaden its potential applications. Here a simple Fabry Perot (FP)
interference technique for measuring, simultaneously, the thermal bump as well as the reflection
phase shift of the gold film used for SPR excitation is reported. The FP signal change is dominated
by the appearance of...[
Read more ]
Surface plasmon resonance (SPR) has found wide applications in sensing down to molecular
level due to its extreme sensitivity to change of dielectric properties. An unavoidable effect in SPR
is surface deformation (thermal bump) due to local heating by incident laser light used in SPR
excitation. In addition, the change in reflection phase from an SPR-supported metal film could
also contribute to the SPR signal variation, and thus proper handling of measured SPR signals is
very important in order to broaden its potential applications. Here a simple Fabry Perot (FP)
interference technique for measuring, simultaneously, the thermal bump as well as the reflection
phase shift of the gold film used for SPR excitation is reported. The FP signal change is dominated
by the appearance of the thermal bump while it is small for the effect of the reflection phase shift
due to the change of dielectric property of the metal. To support the experimental results, model
simulations for the SPR system are performed and good agreement with the experiment is obtained.
The effect of the thermal bump on the resonance of surface plasmon is also investigated and a
polarization-dependent reflection phase shift is observed in SPR. Since both amplitude and phase
can be measured, our method could lead to a better characterization of SPR and can also be applied
to the study of active metasurfaces under external excitation.
Post a Comment