An optimized distributed fiber Bragg grating sensing system based on optical frequency domain reflectometry

Abstract

In this paper, the waveforms in time domain and frequency domain of two kinds of optical frequency domain reflectometry (OFDR) sensing systems are compared, which use common fiber Bragg grating (FBG) and chirped grating, respectively. The results show that chirped fiber grating with about 3 nm of full width at half maximum (FWHM) is helpful to reduce frequency noise evidently and makes the characteristic frequency distinct. OFDR distributed sensing system with chirped grating also offers longer available time, which makes it convenient to measure slow time-varying signal. Such OFDR distributed sensing system is supposed to be more suitable to be applied in bridge health monitoring, and it will improve the accuracy and reliability of the measurement.

Keywords

fiber Bragg grating (FBG) sensor / optical frequency domain reflectometry (OFDR) / strain / chirped grating

References

[1] Childers B A, Froggatt M E, Allison S G, Moore T C, Hare D A, Batten C F, Jegley D C. Use of 3000 Bragg grating strain sensors distributed on four eight-meter optical fibers during static load tests of a composite structure. Proceedings of the Society for Photo-Instrumentation Engineers, 2001, 4332: 133-142

[2] Jegley D C, Bush H G. Structural Testing of a Stitched/Resin Film Infused Graphite-Epoxy Wing Box. NASA LaRC Technical Memorandum, 2001

[3] Wu M C, Prosser W H. Prosser. Simultaneous temperature and strain sensing for cryogenic applications using dual-wavelength fiber Bragg gratings. Proceedings of the Society for Photo-Instrumentation Engineers, 2003, 5191(1): 208

[4] Igawa H, Ohta K, Kasai T, Yamaguchi I, Murayama H, Kageyama K. Distributed measurements with a long gauge FBG sensor using optical frequency domain reflectometry. Journal of Solid Mechanics and Materials Engineering, 2008, 2(9): 1242-1252

[5] Xu M G, Archambault J L, Reekie L, Dakin J P. Discrimination between strain and temperature effects using dual-wavelength fiber grating sensors. Electronics Letters, 1994, 30(13): 1085-1087

[6] Patrick H J, Williams G M, Kersey A D, Pedrazzani J R, Vengsarkar A M. Hybrid fiber Bragg grating/long period fiber grating sensor for strain/temperature discrimination. IEEE Photonics Technology Letters, 1996, 8(9): 1223-1225

[7] Kanellopoulos S E, Handerek V A, Rogers A J. Simultaneous strain and temperature sensing with photogenerated in-fiber gratings. Optics Letters, 1995, 20(3): 333-335

[8] Brady G P, Kalli K, Webb D J, Jackson D A, Reekie L, Archambault J L. Simultaneous measurement of strain and temperature using the first- and second-order diffraction wavelengths of Bragg gratings. IEE Proceedings of Optoelectronics, 1997, 144(3): 156-161

[9] Kersey A D, Davis M A, Patrick H J, LeBlanc M, Koo K P, Askins C G, Putnam M A, Friebele E J. Fiber grating sensors. Journal of Lightwave Technology, 1997, 15(8): 1442-1463

[10] Froggatt M, Moore J. Distributed measurement of static strain in an optical fiber with multiple Bragg gratings at nominally equal wavelengths. Applied Optics, 1998, 37(10): 1741-1746

[11] Froggatt M. Distributed measurement of the complex modulation of a photoinduced Bragg grating in an optical fiber. Applied Optics, 1996, 35(25): 5162-5164

[12] Abdi A M, Suzuki S, Schülzgen A, Kost A R. Fiber bragg grating array calibration. Proceedings of the Society for Photo-Instrumentation Engineers, 2005, 5765: 552-563

Acknowledgements

This work was supported by the Fundamental Research Funds for the Central Universities (No. WHUT 2011-IV-002).

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg