50-km single-ended spontaneous-Brillouin-based distributed-temperature sensor exploiting pulsed Raman amplification.

Area of Science:

• Fiber optic sensing
• Distributed temperature sensing
• Raman spectroscopy

Background:

• Distributed temperature sensing (DTS) is crucial for monitoring infrastructure.
• Traditional Brillouin-based DTS systems face limitations in long-range sensing and spatial resolution.
• Enhancing signal strength in long-haul fiber optics is essential for improved sensor performance.

Purpose of the Study:

• To improve the performance of a single-ended spontaneous-Brillouin-intensity-based distributed-temperature sensor.
• To extend the sensing length and maintain high spatial resolution.
• To investigate the efficacy of Raman amplification for enhancing probe pulse signals in DTS.

Main Methods:

• Utilized a single-ended spontaneous-Brillouin-intensity-based distributed-temperature sensor.
• Implemented Raman amplification by introducing a copropagating pump pulse at 1450 nm within the sensing fiber.
• Tested the sensor system over a sensing length of 50 km with a spatial resolution of 15 m.

Main Results:

• Achieved enhanced performance in a 50 km distributed temperature sensor.
• Demonstrated a spatial resolution of 15 m.
• Reported a standard deviation error of 1°C at the sensor's front end, increasing to less than 13°C at the 50 km mark due to Raman pulse amplification.

Conclusions:

• Raman amplification significantly enhances the performance of long-range distributed temperature sensors.
• The developed system offers a viable solution for 50 km temperature monitoring with improved resolution.
• This technique holds promise for applications requiring precise, long-distance temperature measurements.