Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Polarization-insensitive, omnidirectional fiber-optic ultrasonic sensor with quadrature demodulation

Abstract

We report an ultrasonic sensor system based on a low-finesse Fabry–Perot interferometer (FPI) formed by two weak chirped fiber Bragg gratings (CFBGs) on a coiled single-mode fiber. The sensor system has several desirable features for practical applications in detecting ultrasound on a solid surface. By controlling the birefringence of the fiber coil during the sensor fabrication, the sensor is made insensitive to the polarization variations of the laser source. The circular symmetric structure of the fiber coil also renders the omnidirectional response of the sensor to ultrasound. While the fiber coil is bonded directly to the structure, the CFBGs are suspended from the structure and free from large background strains with little reduction to the sensitivity of the sensor. The low-finesse FPI features a sinusoidal reflection spectrum. Like the conventional phase-generated carried technique, a phase modulator is utilized to implement quadrature demodulation. Therefore, the sensing system is adaptive to large background perturbations experienced by the fiber coil.

© 2020 Optical Society of America

Full Article  |  PDF Article
More Like This
Passive quadrature demodulation of an ultrasonic fiber-optic interferometric sensor using a laser and an acousto-optic modulator

Guigen Liu, Yupeng Zhu, Zigeng Liu, and Ming Han
Opt. Lett. 44(11) 2756-2759 (2019)

Modified phase-generated carrier demodulation of fiber-optic interferometric ultrasound sensors

Farzia Karim, Yupeng Zhu, and Ming Han
Opt. Express 29(16) 25011-25021 (2021)

Supplementary Material (2)

NameDescription
Visualization 1       Spectra of the reference sensor and the polarization-insensitive sensor measured when the laser polarization was varied manually and randomly by a polarization controller.
Visualization 2       Real-time evolution of the signal outputs from the two channels when the operating points were changed by bending the plate.

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (5)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (6)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved