DFB fiber laser static strain sensor based on beat frequency interrogation with a reference fiber laser locked to a FBG resonator.

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 Sε(f) = (4.6 × 10-21) ε2/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.

[2]  P. Ferraro,et al.  Probing the Ultimate Limit of Fiber-Optic Strain Sensing , 2010, Science.

[3]  Zuyuan He,et al.  Sensing the earth crustal deformation with nano-strain resolution fiber-optic sensors. , 2015, Optics express.

[4]  P. Ferraro,et al.  Ultra-high sensitivity frequency-comb-referenced multi-parametric sensors based on 1-D photonic components , 2008, Organic Photonics + Electronics.

[5]  Zuyuan He,et al.  Sub-nano resolution fiber-optic static strain sensor using a sideband interrogation technique. , 2012, Optics letters.

[6]  T. Giallorenzi,et al.  Homodyne Demodulation Scheme for Fiber Optic Sensors Using Phase Generated Carrier , 1982 .

[7]  Fang Li,et al.  ${\pi}$-Phase-Shifted FBG for High-Resolution Static-Strain Measurement Based on Wavelet Threshold Denoising Algorithm , 2014, Journal of Lightwave Technology.

[8]  Pietro Ferraro,et al.  Design and test of a laser-based optical-fiber Bragg-grating accelerometer for seismic applications , 2008 .

[9]  P. Laporta,et al.  Fiber strain sensor based on a pi-phase-shifted Bragg grating and the Pound-Drever-Hall technique. , 2008, Optics express.

[10]  Fang Li,et al.  A Cross-Correlation Method in Wavelet Domain for Demodulation of FBG-FP Static-Strain Sensors , 2014, IEEE Photonics Technology Letters.

[11]  G. A. Cranch,et al.  Distributed Feedback Fiber Laser Strain Sensors , 2008, IEEE Sensors Journal.

[12]  Hwa-Yaw Tam,et al.  Dual polarization fiber grating laser hydrophone. , 2009, Optics express.

[13]  C. E. Campanella,et al.  Split-mode fiber Bragg grating sensor for high-resolution static strain measurements. , 2014, Optics letters.

[14]  Fang Li,et al.  Distributed feedback fiber laser for sub-nanostrain-resolution static strain measurement by use of swept beat-frequency demodulation , 2015, Asia Pacific Optical Sensors Conference.

[15]  P.K. Cheo,et al.  Effects of Yb:Er-codoping on suppressing self-pulsing in Er-doped fiber lasers , 1997, IEEE Photonics Technology Letters.

[16]  Alan D. Kersey,et al.  Fibre laser sensor with ultrahigh strain resolution using interferometric interrogation , 1995 .

[17]  Malcolm B. Gray,et al.  Quasi-static fiber strain sensing with absolute frequency referencing , 2008, International Conference on Optical Fibre Sensors.

[18]  Fang Li,et al.  Swept optical SSB-SC modulation technique for high-resolution large-dynamic-range static strain measurement using FBG-FP sensors. , 2015, Optics letters.

[19]  Fang Li,et al.  Fiber laser sensing system and its applications , 2011 .

[20]  M Ibsen,et al.  Distributed-feedback fiber laser sensor for simultaneous strain and temperature measurements operating in the radio-frequency domain. , 2001, Applied optics.

[21]  Kazuo Hotate,et al.  An ultra-high-resolution FBG static-strain sensor for geophysics applications , 2010, European Workshop on Optical Fibre Sensors.

[22]  Daniel A Shaddock,et al.  High-resolution absolute frequency referenced fiber optic sensor for quasi-static strain sensing. , 2010, Applied optics.

[23]  Moshe Tur,et al.  Static fiber-Bragg grating strain sensing using frequency-locked lasers , 1999 .