Surface plasmon resonance optical cavity enhanced refractive index sensing
We report on a method for surface plasmon resonance (SPR) refractive index sensing based on direct time-domain measurements. An optical resonator is built around an SPR sensor, and its photon lifetime is measured as a function of loss induced by refractive index variations. The method does not rely...
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Published in | Optics letters Vol. 38; no. 11; p. 1951 |
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Main Authors | , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.06.2013
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Subjects | |
Online Access | Get more information |
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Summary: | We report on a method for surface plasmon resonance (SPR) refractive index sensing based on direct time-domain measurements. An optical resonator is built around an SPR sensor, and its photon lifetime is measured as a function of loss induced by refractive index variations. The method does not rely on any spectroscopic analysis or direct intensity measurement. Time-domain measurements are practically immune to light intensity fluctuations and thus lead to high resolution. A proof of concept experiment is carried out in which a sensor response to liquid samples of different refractive indices is measured. A refractive index resolution of the current system, extrapolated from the reproducibility of cavity-decay time determinations over 133 s, is found to be about 10(-5) RIU. The possibility of long-term averaging suggests that measurements with a resolution better than 10(-7) RIU/√Hz are within reach. |
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ISSN: | 1539-4794 |
DOI: | 10.1364/OL.38.001951 |