57-km single-ended spontaneous Brillouin-based distributed fiber temperature sensor using microwave coherent...

Area of Science:

• Fiber optic sensing
• Applied physics
• Metrology

Background:

• Distributed fiber optic sensing enables remote temperature monitoring.
• Spontaneous Brillouin scattering is a key phenomenon in optical fibers.
• Accurate temperature measurements are crucial in various industrial applications.

Purpose of the Study:

• To develop a novel single-ended technique for distributed fiber temperature measurements.
• To utilize microwave heterodyne detection for enhanced signal processing.
• To leverage spontaneous Brillouin scattering for temperature sensing.

Main Methods:

• Single-ended distributed fiber temperature measurement.
• Microwave heterodyne detection.
• Spontaneous Brillouin scattering analysis.
• Brillouin frequency-shift measurements over 57 km sensing length.
• Spatial resolution of 20 m.

Main Results:

• Successful Brillouin frequency-shift measurements obtained.
• Achieved a sensing length of 57 km with 20 m spatial resolution.
• Demonstrated a root-mean-square (rms) error of less than 3 MHz at the far end.
• Quantified the temperature dependence as 1.07±0.06 MHz/K.

Conclusions:

• The presented technique offers a viable method for long-range, high-resolution distributed fiber temperature sensing.
• Microwave heterodyne detection enhances the accuracy and performance of Brillouin scattering-based sensors.
• The results demonstrate the potential for practical applications requiring precise remote temperature monitoring.