Enhancing Distributed Sensing with a Dual-Brillouin-Peak Optical Fiber
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Dual-Brillouin-Peak Optical Fiber was designed and fabricated by researchers from OFS
In an era of advanced sensing technologies, the dual-Brillouin-peak optical fiber emerges as a new practical solution forresolving the strain-temperature cross-sensitivity that exists in almost all optical fiber sensors. Its potential spans across a multitude of fields, demanding precision over long distances and high resolutions. This groundbreaking technology is set to redefine the boundaries of Brillouin scattering based distributed fiber sensing.
Dual-Brillouin-peak single-mode optical fiber can measure both strain and temperature at the same time. This is a very useful feature for applications such as structural health monitoring, oil and gas exploration, and power transmission.
Dual-Brillouin-peak single-mode optical fiber has two distinct peaks in its Brillouin gain spectrum with similar amplitude levels. By measuring the frequency shifts of these two peaks, we can determine both the strain and the temperature along the fiber.
This is different from conventional single-mode optical fibers, which have only one dominant Brillouin peak and can only measure either strain or temperature, but not both at the same time. To measure both parameters, we would need to use two different fibers or a special fiber with a coating that has a different thermal expansion coefficient that usually results in an ill-conditioned discrimination.
The dual-Brillouin-peak optical fiber has several advantages over these methods. First, it simplifies the measurement system by reducing the number of components and connections. Second, it eliminates the need for calibration or compensation of the thermal expansion coefficient. Third, it increases the accuracy and resolution of the measurements by enhancing the Brillouin gain of the higher-order acoustic mode.
The researchers demonstrated the performance of their optical fiber in a 25-kilometer sensing length with 5-meter spatial resolution. They achieved a temperature resolution of 2°C and a strain resolution of 40 microstrain.
The fiber and standard single-mode telecom fibers are interchangeable with low splicing loss. The fiber is fully compatible with existing BOTDR/BOTDA (Brillouin Optical Time Domain Reflectometer/Analyzer) interrogators in the market. The dual-Brillouin-peak optical fiber is a promising technology for simultaneous distributed strain and temperature measurement. It has potential applications in various fields that require long-distance and high-resolution sensing.
To learn more, read the whitepaper: Request PDF | OFS (ofsoptics.com)