Twice-FFT demodulation for signal distortion in optical fiber FP acoustic sensor.
Heliyon
; 6(12): e05790, 2020 Dec.
Article
in En
| MEDLINE
| ID: mdl-33364516
ABSTRACT
A Twice-FFT demodulation method for signal distortion state is proposed and experimentally demonstrated in an optical fiber Fabry-Perot (FP) acoustic sensor. Here the fiber FP acoustic sensor element is build with fiber end face and combination of diaphragms which is composed of a small round aluminum foil and a polymer PET film. The hypotenuse intensity demodulation method is applied to acquire the acoustic signal in time domain assisted with a Photodetector (PD) and an oscilloscope. The first Fast Fourier transform (FFT) processing results show harmonic distortion on the frequency domain spectrum. To demodulate the acoustic frequency and amplitude information, twice-FFT processing is preformed. Experimental results reveal an accuracy up to 95.6% of acoustic signal in the frequency range 2-100 Hz. Our scheme provides a new option for signal demodulation of optical fiber acoustic sensors (OFAS).
Full text:
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Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Heliyon
Year:
2020
Document type:
Article