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A 100-km BOFDA Assisted by First-Order Bi-Directional Raman Amplification
Thomas Kapa1, Andy Schreier2, Katerina Krebber3
1Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, 12205 Berlin, Germany. thomas.kapa@bam.de.
Sensors (Basel, Switzerland)
|April 3, 2019
Summary
This study demonstrates a 100-km Brillouin Optical Frequency-Domain Analysis (BOFDA) using a 200-km fiber loop. Enhanced sensor accuracy and spatial resolution were achieved using distributed Raman amplification and a digital high-pass filter.
Area of Science:
- Optoelectronics
- Fiber optic sensing
- Distributed sensing
Background:
- Brillouin Optical Frequency-Domain Analysis (BOFDA) is a technique for measuring strain and temperature in optical fibers.
- Previous BOFDA systems were limited in sensing distance and spatial resolution.
- Enhancements in amplification and filtering are crucial for extending the reach and precision of fiber optic sensors.
Purpose of the Study:
- To present a 100-km Brillouin Optical Frequency-Domain Analysis (BOFDA) system for the first time.
- To improve sensor length, accuracy, and spatial resolution compared to previous work.
- To demonstrate the system's capability for long-range temperature measurements.
Main Methods:
- Implementation of a 100-km BOFDA system within a 200-km fiber loop.
- Application of distributed Raman amplification (DRA) to enhance signal strength over long distances.
- Utilization of a digital high-pass filter to improve signal processing and reduce noise.
Main Results:
- Successful temperature measurements were conducted over sensing distances of 75 km and 100 km.
- A spatial resolution of 12.5 meters was maintained throughout the sensing length.
- The system detected temperature changes of 5°C along 75 km and 30°C at 99.5 km.
Conclusions:
- The developed 100-km BOFDA system represents a significant advancement in long-range fiber optic sensing.
- Distributed Raman amplification and digital filtering effectively enhance sensor performance.
- The system shows high potential for accurate, long-distance temperature monitoring applications.
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