Compact Fabry–Pérot Fiber-Optic Sensor for Dual Acoustic and Temperature Detection
Journal
IEEE Sensors Journal
ISSN
1530437X
Date Issued
2026
Author(s)
Li, Lieber Po-Hung
Wu, Yi-Cin
Dinh, Quoc-Thinh
Huang, Wei-Hsuan
Pham, Thi-Thu-Hien
Chen, Yu-Bin
Liu, Cheng-Yang
Abstract
A micro-scale fiber-optic sensor based on the Fabry-Pérot interferometric principle is proposed and experimentally demonstrated. The device comprises a single-mode optical fiber, a hollow-core capillary, and an ultrathin metallic diaphragm, forming a compact sensor structure with advantages of low fabrication cost, simple manufacturing, and ultra-small dimensions. The dual-parameter sensing strategy exploits time-scale separation and complementary demodulation domains, using intensity-based demodulation at a fixed quadrature point to capture fast acoustic-induced phase perturbations, while temperature sensing is achieved by tracking the slow spectral drift of the interference fringes caused by thermal expansion and thermo-optic effects. Comprehensive multiphysics experiments were conducted to evaluate both acoustic and thermal sensing capabilities, with emphasis on the effect of diaphragm thickness on overall performance. Acoustic characterization revealed a wide frequency response from 10 Hz to 20 kHz, a maximum signal-to-noise ratio of 46.1 dB, a minimum total harmonic distortion of 0.051%, and a minimum detectable pressure of 12.9 μPa/√Hz at 1 kHz. Thermal measurements confirmed reliable operation over 50 °C - 300 °C, achieving a sensitivity of 13.3 pm/°C with excellent linearity (R2 > 0.99). These results demonstrate that the proposed Fabry-Pérot fiber-optic sensor provides high-performance and cost-effective solutions for applications in acoustic detection, temperature monitoring, and wearable sensing technologies.
Subjects
Acoustic detection
Fabry-Pérot interferometer
fiber-optic sensor
temperature sensing
thin film
Publisher
Institute of Electrical and Electronics Engineers Inc.
Type
journal article