Open AccessDFB fiber laser static strain sensor based on beat frequency interrogation with a reference fiber laser locked to a FBG resonator
Author(s) -
Wenzhu Huang,
Shengwen Feng,
Wentao Zhang,
Fang Li
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.012321
Subject(s) - materials science , optics , fiber bragg grating , laser , fiber laser , distributed feedback laser , resonator , beat (acoustics) , laser power scaling , fiber optic sensor , polarization maintaining optical fiber , optoelectronics , optical fiber , physics
We report on a high-resolution static strain sensor developed with distributed feedback (DFB) fiber laser. A reference FBG resonator is used for temperature compensation. Locking another independent fiber laser to the resonator using the Pound-Drever-Hall technique results in a strain power spectral density better than S ε (f) = (4.6 × 10 -21 ) ε 2 /Hz in the frequency range from 1 Hz to 1 kHz, corresponding to a minimum dynamic strain resolution of 67.8 pε/√Hz. This frequency stabilized fiber laser is proposed to interrogate the sensing DFB fiber laser by the beat frequency principle. As a reasonable DFB fiber laser setup is realized, a narrow beat frequency line-width of 3.23 kHz and a high beat frequency stability of 0.036 MHz in 15 minutes are obtained in the laboratory test, corresponding to a minimum static strain resolution of 270 pε. This is the first time that a sub-0.5 nε level for static strain measurement using DFB fiber laser is demonstrated.