Distributed measurement of chemicals using fiber optic evanescent wave sensing

Jochen Buerck; Elke Sensfelder; Hans-Joachim Ache

doi:10.1117/12.260599

10 December 1996 Distributed measurement of chemicals using fiber optic evanescent wave sensing

Jochen Buerck, Elke Sensfelder, Hans-Joachim Ache

Proceedings Volume 2836, Chemical, Biochemical, and Environmental Fiber Sensors VIII; (1996) https://doi.org/10.1117/12.260599
Event: SPIE's 1996 International Symposium on Optical Science, Engineering, and Instrumentation, 1996, Denver, CO, United States

Abstract

A truly distributed sensing system for nonpolar organic chemicals has been built up by adapting a chemically sensitive polymer-clad silica fiber to an optical time domain reflectometry (OTDR) set-up. This arrangement allows to measure the time delay between a short light pulse entering the fiber and the discrete signals of backscattered light caused by chemical effects in the fiber cladding. The backscatter signals originate from changes in the light guiding properties of the fiber, which are affected by the enrichment of chemicals in the cladding through the evanescent wave. The shape and magnitude of signals caused by penetrating chemicals either due to changes in refractive index, or absorption and fluorescence properties of the fiber cladding, have been examined. Changes in the optical properties of the cladding were produced either by contacting the fiber with solvents (e.g. tetrachloroethane) or organic dyes such as methylene blue and rhodamine 800. Typical parameters, that influence the intensity of the OTDR response signal are the refractive index, concentration and molar absorptivity of the analyte, as well as the power of the light source.

Citation Download Citation

Jochen Buerck, Elke Sensfelder, and Hans-Joachim Ache "Distributed measurement of chemicals using fiber optic evanescent wave sensing", Proc. SPIE 2836, Chemical, Biochemical, and Environmental Fiber Sensors VIII, (10 December 1996); https://doi.org/10.1117/12.260599

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available