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Evanescent Field Based Photoacoustics: Optical Property Evaluation at Surfaces
Published on: July 26, 2016
Quantitative studies of evanescent wave intensity profiles using optical fluorescence
Applied Optics
|June 16, 2010
Summary
Evanescent wave-induced fluorescence accurately measures optical energy density at solid-solution interfaces. This technique validates using fluorescence intensity as a Laplace transform for studying polymer layers near surfaces.
Area of Science:
- Physical Chemistry
- Surface Science
- Spectroscopy
Background:
- Optical evanescent waves are generated at solid-solution interfaces via total internal reflection.
- Understanding energy density profiles is crucial for interfacial phenomena.
- Fluorescence from chromophores can probe these interfacial properties.
Purpose of the Study:
- To probe the energy density profile of optical evanescent waves using fluorescence.
- To validate the evanescent wave-induced fluorescence technique for interfacial studies.
- To confirm the assumption of fluorescence intensity as a Laplace transform of polymer concentration profiles.
Main Methods:
- Utilized uniformly distributed chromophores in an organic solution.
- Generated optical evanescent waves via total internal reflection at a silica-solution interface.
- Measured fluorescence intensity from an aqueous fluorescein solution.
Main Results:
- Observed fluorescence intensity showed good quantitative agreement with the predicted exponential decay of optical energy.
- The results support the application of evanescent wave-induced fluorescence for interfacial analysis.
- Validated the assumption that fluorescence intensity directly relates to the Laplace transform of polymer concentration profiles.
Conclusions:
- The evanescent wave-induced fluorescence technique is a reliable method for probing interfacial energy density.
- This technique can be effectively used to study polymer adsorption and depletion layers near solid surfaces.
- The mathematical assumption linking fluorescence intensity to polymer concentration profiles is experimentally validated.
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