High-resolution distributed shape sensing using phase-sensitive optical time-domain reflectometry and multicore...

Area of Science:

• Fiber optics sensing
• Optical metrology
• Distributed sensing systems

Background:

• Traditional shape sensing methods often face limitations in sensitivity, spatial resolution, and cross-sensitivity to environmental factors like temperature.
• Multicore fibers (MCF) offer potential for enhanced sensing capabilities due to their complex internal structure.
• Phase-sensitive optical time-domain reflectometry (φ-OTDR) is a technique for high-resolution distributed sensing.

Purpose of the Study:

• To propose and experimentally demonstrate a highly-sensitive distributed shape sensor.
• To leverage multicore fiber (MCF) and phase-sensitive optical time-domain reflectometry (φ-OTDR) for shape sensing.
• To overcome cross-sensitivity issues between strain and temperature in distributed sensing.

Main Methods:

• Utilizing a multicore fiber (MCF) as the sensing element.
• Employing phase-sensitive optical time-domain reflectometry (φ-OTDR) for signal interrogation.
• Experimentally validating the system's performance in terms of sensitivity, spatial resolution, and repeatability.

Main Results:

• Achieved high strain sensitivity down to approximately 0.3 µɛ over a 24 m MCF.
• Demonstrated a spatial resolution of 10 cm for shape measurements.
• Successfully retrieved fiber shape changes, detecting displacements as small as 50 µm.
• Showcased the technique's ability to overcome cross-sensitivity between strain and temperature.

Conclusions:

• The proposed MCF-based φ-OTDR system represents the first demonstration of distributed shape sensing using this combination.
• The developed sensor exhibits high sensitivity, good repeatability, and robustness against temperature variations.
• This technique holds significant promise for advanced applications in dynamic, long-distance, and 3D distributed shape sensing.