A C-OTDR Sensor for Liquid Detection Based on Optically Heated Co2+-Doped Fibers

• Published in: IEEE sensors journal Vol. 20; no. 17; pp. 10154 - 10158
• Main Authors: Coscetta, A., Catalano, E., Cerri, E., Cennamo, N., Zeni, Luigi, Minardo, Aldo
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-09-2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acetone; Cobalt; coherent-OTDR; Distributed acoustic sensors; Doped fibers; Heating systems; liquid detection; Liquids; Optical fiber sensors; Optical fibers; Optical pumping; Reflectometers; Vibration measurement
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2020.2991224

In this paper, we propose a dual wavelength scheme for the detection of liquids based on optically absorbing (Co 2+ -doped) optical fibers. The proposed configuration makes use of a Coherent-Optical Time Domain Reflectometer (C-OTDR) operating with standard fibers at 850 nm. Besides vibration measurements over all the sensing fiber, the proposed scheme performs liquid detection in short sections of Co 2+ -doped fibers, heated by a modulated optical pump at 1550 nm. We demonstrate that the proposed sensor detects the liquids surrounding the doped fiber, such as water or acetone.