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Title: Development of Sensors Using Evanescent Wave Interactions in Sapphire Optical Fibers

Abstract

The development of tunable diode laser absorption sensors for measurements in industrial boilers, both through direct absorption and evanescent wave absorption have been performed in the work presented here. These sensors use both direct and indirect absorption through the use of evanescent interactions within a coal firing combustion environment. For the direct absorption sensor, wavelength modulation absorption spectroscopy with second-harmonic detection was implemented within a physical probe designed to be placed with the flue stack of a power plant. Measurements were taken of carbon dioxide and water vapor concentration during operation at a local industrial facility. The design of this sensor probe overcomes problems of beam steering and permits a reference gas measurement. Extracted concentration data and design elements from the direct absorption measurements are presented. In addition, development of a sapphire fiber-based sensor using evanescent wave absorption along the outside of the fiber is presented. Evanescent absorption allows for the laser transmission to be maintained in the fiber at all times and may alleviate problems of background emission, beam steering, and especially scattering of the laser beam from solid particles experienced through free path direct absorption measurements in particulated flows. Laboratory measurements using evanescent fiber detection are presented.

Authors:
;
Publication Date:
Research Org.:
University Of Connecticut
Sponsoring Org.:
USDOE
OSTI Identifier:
923025
DOE Contract Number:
FG26-06NT42688
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; ABSORPTION; ABSORPTION SPECTROSCOPY; BOILERS; CARBON DIOXIDE; COAL; COMBUSTION; DESIGN; DETECTION; FIBERS; LASERS; MODULATION; OPTICAL FIBERS; POWER PLANTS; PROBES; SAPPHIRE; SCATTERING; WATER VAPOR; WAVELENGTHS

Citation Formats

Michael W. Renfro, and Eric H. Jordan. Development of Sensors Using Evanescent Wave Interactions in Sapphire Optical Fibers. United States: N. p., 2006. Web. doi:10.2172/923025.
Michael W. Renfro, & Eric H. Jordan. Development of Sensors Using Evanescent Wave Interactions in Sapphire Optical Fibers. United States. doi:10.2172/923025.
Michael W. Renfro, and Eric H. Jordan. Sun . "Development of Sensors Using Evanescent Wave Interactions in Sapphire Optical Fibers". United States. doi:10.2172/923025. https://www.osti.gov/servlets/purl/923025.
@article{osti_923025,
title = {Development of Sensors Using Evanescent Wave Interactions in Sapphire Optical Fibers},
author = {Michael W. Renfro and Eric H. Jordan},
abstractNote = {The development of tunable diode laser absorption sensors for measurements in industrial boilers, both through direct absorption and evanescent wave absorption have been performed in the work presented here. These sensors use both direct and indirect absorption through the use of evanescent interactions within a coal firing combustion environment. For the direct absorption sensor, wavelength modulation absorption spectroscopy with second-harmonic detection was implemented within a physical probe designed to be placed with the flue stack of a power plant. Measurements were taken of carbon dioxide and water vapor concentration during operation at a local industrial facility. The design of this sensor probe overcomes problems of beam steering and permits a reference gas measurement. Extracted concentration data and design elements from the direct absorption measurements are presented. In addition, development of a sapphire fiber-based sensor using evanescent wave absorption along the outside of the fiber is presented. Evanescent absorption allows for the laser transmission to be maintained in the fiber at all times and may alleviate problems of background emission, beam steering, and especially scattering of the laser beam from solid particles experienced through free path direct absorption measurements in particulated flows. Laboratory measurements using evanescent fiber detection are presented.},
doi = {10.2172/923025},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Dec 31 00:00:00 EST 2006},
month = {Sun Dec 31 00:00:00 EST 2006}
}

Technical Report:

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