Abstract
We propose and demonstrate a dynamic Brillouin optical fiber sensing based on the multi-slope assisted fast Brillouin optical time-domain analysis (F-BOTDA), which enables the measurement of a large strain with real-time data processing. The multi-slope assisted F-BOTDA is realized based on the double-slope demodulation and frequency-agile modulation, which significantly increases the measurement range compared with the single- or double- slope assisted F-BOTDA, while maintaining the advantage of fast data processing and being suitable for real-time on-line monitoring. A maximum strain variation up to 5000μϵ is measured in a 32-m fiber with a spatial resolution of ∼1m and a sampling rate of 1kHz. The frequency of the strain is 12.8Hz, which is limited by the rotation rate of the motor used to load the force on the fiber. Furthermore, the influence of the frequency difference between two adjacent probe tones on the measurement error is studied theoretically and experimentally for optimization. For a Brillouin gain spectrum with a 78-MHz width, the optimum frequency difference is ∼40MHz. The measurement error of Brillouin frequency shift is less than 3MHz over the whole measurement range (241MHz).
| Original language | English |
|---|---|
| Pages (from-to) | 9781-9793 |
| Number of pages | 13 |
| Journal | Optics Express |
| Volume | 24 |
| Issue number | 9 |
| DOIs | |
| State | Published - 2 May 2016 |
Bibliographical note
Funding Information:Thanks to Prof. Avi Zadok, who gave me valuable suggestions on this paper. This work is supported by the 863 Program of China 2014AA110401, the National Key Scientific Instrument and Equipment Development Project 2013YQ040815, the NSF of China 61575052 and 61308004, the National Key Technology Research and Development Program of the Ministry of Science and Technology of China 2014BAG05B07, the Foundation for Talents Returning from Overseas of Harbin 2013RFLXJ013, the Scientific Research Fund of Heilongjiang Provincial Education Department 12531093, the Fundamental Research Funds for the Central Universities HIT. NSRIF. 2015041, the National Key Laboratory Funds for National Key Laboratory of Science and Technology on Tunable Laser and the Heilongjiang Postdoctoral Fund LBH-Z15076.
Publisher Copyright:
©2016 Optical Society of America.