Pipeline Monitoring Using Highly Sensitive Vibration Sensor Based on Fiber Ring Cavity Laser

Area of Science:

• Photonics and Optical Sensing
• Fiber Optic Sensors
• Acoustic Emission Monitoring

Background:

• Traditional vibration sensors face limitations in sensitivity and bandwidth.
• Fiber optic sensors offer advantages in remote sensing and immunity to electromagnetic interference.
• Accurate acoustic emission monitoring is crucial for structural health assessment.

Purpose of the Study:

• To propose and demonstrate a novel vibration fiber sensor.
• To enhance signal-to-noise ratio for improved detection.
• To validate the sensor's performance in a real-world pipeline monitoring scenario.

Main Methods:

• Integration of a single-mode-multimode-single-mode (SMS) fiber structure within a fiber ring cavity laser.
• Optimization of the ring laser's lasing wavelength to the SMS transmission spectrum's maximum gain region.
• Experimental testing across a wide frequency range (10 Hz to 400 kHz) and field deployment for pipeline monitoring.

Main Results:

• Successful demonstration of a vibration fiber sensor with a fiber ring cavity laser and SMS structure.
• Achieved a high signal-to-noise ratio by tuning the laser wavelength to the optimal biasing point.
• Validated real-time vibration monitoring on an 18" pipeline using induced vibrations.

Conclusions:

• The proposed fiber optic vibration sensor system is highly sensitive and effective.
• The system enables real-time acoustic emission monitoring for pipelines.
• This technology holds significant potential for structural health monitoring applications.