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

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. Additionally, 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 ofmore » 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.« less

Authors:

Sweeney, Daniel C.  ^[1];

• Search DOE PAGES for author "Sweeney, Daniel C."
• Search DOE PAGES for ORCID "0000-0002-1289-1627"

Schrell, Adrian M. ^[1]; Liu, Yun  ^[1];

• Search DOE PAGES for author "Liu, Yun"
• Search DOE PAGES for ORCID "0000-0001-9843-2757"

Petrie, Christian M.  ^[1]

• Search DOE PAGES for author "Petrie, Christian M."
• Search DOE PAGES for ORCID "0000-0003-1167-3545"

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+ Show Author Affiliations

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:

Wed May 27 00:00:00 EDT 2020

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Nuclear Energy (NE)

OSTI Identifier:

1633156

Alternate Identifier(s):

OSTI ID: 2325132

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Sensors and Actuators. A, Physical

Additional Journal Information:

Journal Volume: 312; Journal Issue: C; Journal ID: ISSN 0924-4247

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

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