Comparison of the use of first and second-order Raman amplification to assist a phase-sensitive optical time domain reflectometer in distributed vibration sensing over 125 km

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Research areas:
Year:
2014
Type of Publication:
In Proceedings
Authors:
  • Martins, HF
  • Martin-Lopez, S
  • Filograno, ML
  • Corredera, P
  • Frazão, O
  • Gonzalez-Herraez, M
Volume:
9157
Book title:
OFS2014 23rd International Conference on Optical Fiber Sensors
Pages:
91576K-91576K
Organization:
International Society for Optics and Photonics
Month:
June
BibTex:
Abstract:
We report on the use of second-order Raman amplification to assist a phase-sensitive optical time domain reflectometer (ΦOTDR ) used for vibration measurements over very long distances. The sensor was able to measure vibrations of up to 380 Hz (limit set by the time of flight of light pulses) in a distance of 125 km with a resolution of 10 m and no post-processing. Balanced detection is used to reduce the relative intensity noise. A comparison with a sensor using first-order Raman amplification under similar conditions is presented and a clear improvement of performance is demonstrated.