Metal-embedded fiber optic sensor packaging and signal demodulation scheme towards high-frequency dynamic measurements in harsh environments

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

Optical fiber-based sensors are commonly used for industrial monitoring and control processes due to their small size, resistance to electromagnetic interference, and ability to perform a wide variety of high-precision measurements. However, implementing optical fiber sensors in harsh environments is challenging because they are small and fragile. Proper packaging of fiber-optic sensors could extend their use to harsh environments, including at high temperature and under high radiation. Furthermore, conventional fiber optic-based measurement systems often use computationally expensive signal processing algorithms which hinder their use in high-frequency dynamic applications. This work reports on the design of an optical fiber-pressure sensor system based on low-coherence interferometry that uses a metal-embedded optical fiber to provide a robust sensor package. A novel phase demodulation scheme is proposed to extract length changes from the deformation of a thin diaphragm within a Fabry–Pérot cavity to measure pressure. The sensor has been tested to ±100 kPa, has a theoretical linear response over a ±270 kPa dynamic range (24 dB maximum signal-to-noise ratio), and can resolve pressure transients up to 3910 kPa/s. Sampling at 100 kHz, the present sensor can resolve 2 kPa dynamic pressures at frequencies up to 2 kHz. Faster transients on the order of tens to hundreds of kHz can theoretically be resolved at the expense of decreasing the maximum resolvable amplitude. A methodology for designing a LCI pressure sensor for a given application is outlined based on the limitations imposed by the Nyquist criterion, the diaphragm's resonant frequency, the LCI optoelectronics, and the phase demodulation scheme. The sensor is the first to implement a low-coherence light source and a Fabry–Pérot interferometer designed to provide real-time high-fidelity pressure measurements using a metal-embedded optical fiber. The demonstrated sensor provides a platform for sensing in harsh conditions such as in nuclear and energy applications.

Original languageEnglish
Article number112075
JournalSensors and Actuators A: Physical
Volume312
DOIs
StatePublished - Sep 1 2020

Funding

This research was originally sponsored by the Laboratory Directed Research and Development (LDRD) Program at Oak Ridge National Laboratory (ORNL), managed by UT-Battelle, LLC, for the US Department of Energy. Following successful completion of the LDRD project, this work was integrated into the Versatile Test Reactor (VTR) Program of the Department of Energy, Office of Nuclear Energy for optical fiber sensing application in future VTR irradiation experiments. The authors would like to acknowledge Bing Qi (ORNL) for his invaluable help in assembling the LCI optics used in this study, Doug Kyle (ORNL) for welding the sensor assembly, and Ricardo Muse (ORNL) for developing the initial data acquisition software. They would also like to thank Adam Hehr and Mark Norfolk (Fabrisonic, LLC) for providing the metal-embedded fiber optics. Carlos Jones (ORNL) provided photographs of the sensor assembly. This research was originally sponsored by the Laboratory Directed Research and Development (LDRD) Program at Oak Ridge National Laboratory (ORNL), managed by UT-Battelle, LLC, for the US Department of Energy. Following successful completion of the LDRD project, this work was integrated into the Versatile Test Reactor (VTR) Program of the Department of Energy, Office of Nuclear Energy for optical fiber sensing application in future VTR irradiation experiments. The authors would like to acknowledge Bing Qi (ORNL) for his invaluable help in assembling the LCI optics used in this study, Doug Kyle (ORNL) for welding the sensor assembly, and Ricardo Muse (ORNL) for developing the initial data acquisition software. They would also like to thank Adam Hehr and Mark Norfolk (Fabrisonic, LLC) for providing the metal-embedded fiber optics. Carlos Jones (ORNL) provided photographs of the sensor assembly. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).

FundersFunder number
Adam Hehr and Mark Norfolk
US Department of Energy
UT-Battelle
U.S. Department of Energy
Office of Nuclear Energy
Oak Ridge National Laboratory
Laboratory Directed Research and Development
UT-Battelle

    Fingerprint

    Dive into the research topics of 'Metal-embedded fiber optic sensor packaging and signal demodulation scheme towards high-frequency dynamic measurements in harsh environments'. Together they form a unique fingerprint.

    Cite this