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Fourier Transform-Plasmon Waveguide Spectroscopy: A Nondestructive Multifrequency Method for Simultaneously Determining Polymer Thickness and Apparent Index of Refraction
Analytical Chemistry
  • Jonathan M. Bobbitt, Iowa State University
  • Stephen C. Weibel, GWC Technologies Inc.
  • Moneium Elshobaki, Mansoura University, Egypt
  • Sumit Chaudhary, Iowa State University
  • Emily A. Smith, Iowa State University
Document Type
Article
Publication Version
Published Version
Publication Date
11-20-2014
DOI
10.1021/ac504103g
Abstract
Fourier transform (FT)-plasmon waveguide resonance (PWR) spectroscopy measures light reflectivity at a waveguide interface as the incident frequency and angle are scanned. Under conditions of total internal reflection, the reflected light intensity is attenuated when the incident frequency and angle satisfy conditions for exciting surface plasmon modes in the metal as well as guided modes within the waveguide. Expanding upon the concept of two-frequency surface plasmon resonance developed by Peterlinz and Georgiadis [Opt. Commun. 1996, 130, 260], the apparent index of refraction and the thickness of a waveguide can be measured precisely and simultaneously by FT-PWR with an average percent relative error of 0.4%. Measuring reflectivity for a range of frequencies extends the analysis to a wide variety of sample compositions and thicknesses since frequencies with the maximum attenuation can be selected to optimize the analysis. Additionally, the ability to measure reflectivity curves with both p- and s-polarized light provides anisotropic indices of refraction. FT-PWR is demonstrated using polystyrene waveguides of varying thickness, and the validity of FT-PWR measurements are verified by comparing the results to data from profilometry and atomic force microscopy (AFM).
Comments

Reprinted (adapted) with permission from Analytical Chemistry, 86(24); 11957-11961. Doi: 10.1021/ac504103g. Copyright 2014 American Chemical Society.

Copyright Owner
American Chemical Society
Language
en
File Format
application/pdf
Citation Information
Jonathan M. Bobbitt, Stephen C. Weibel, Moneium Elshobaki, Sumit Chaudhary, et al.. "Fourier Transform-Plasmon Waveguide Spectroscopy: A Nondestructive Multifrequency Method for Simultaneously Determining Polymer Thickness and Apparent Index of Refraction" Analytical Chemistry Vol. 86 Iss. 24 (2014) p. 11957 - 11961
Available at: http://works.bepress.com/sumit-chaudhary/5/