Abstract
A fiber optic chemical sensor based on gold-island surface plasmon excitation is presented. The sensing part of the fiber is a one inch portion on which cladding has been removed and onto which a thin layer of gold has been deposited to form a particulate surface. Annealing the gold reshapes the particles and produces an absorbance near 535 nm when the only medium residing outside the surface is air. A range of wavelengths provided by a white light source and monochromator is launched through the optical fiber. The transmitted spectra display shifts in the resonance absorption due to any changes in the medium surrounding, or adsorbed onto the fiber. Experimental results for the sensitivity and dynamic range in the measurement of liquid solutions are in agreement with a basic theoretical model which characterizes the surface plasmon using nonretarded electrodynamics. Furthermore, the model assumes the particles are isolated oblate spheroids with a distribution of eccentricities.
Original language | English |
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Pages (from-to) | 106-117 |
Number of pages | 12 |
Journal | Sensors and Actuators, B: Chemical |
Volume | 54 |
Issue number | 1 |
DOIs | |
State | Published - Jan 25 1999 |
Externally published | Yes |
Funding
The authors are grateful to Dr P.I. Oden for his help on the acquisition of the SEM and AFM pictures of the samples. Oak Ridge National Laboratory is managed by Lockheed Martin Energy Research Corporation for the US Department of Energy under contract number DE-AC05-960R22464.