Campus Units

Chemistry, Electrical and Computer Engineering, Materials Science and Engineering, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

11-20-2014

Journal or Book Title

Analytical Chemistry

Volume

86

Issue

24

First Page

11957

Last Page

11961

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

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