A threaded curvature-controlled optical fiber for large transient displacement sensing

Area of Science:

• Optoelectronics
• Fiber Optic Sensors
• Mechanical Engineering

Background:

• Accurate measurement of large transient displacements is crucial for monitoring flexible structures.
• Existing methods often face limitations in sensitivity, dynamic range, or manufacturing complexity.
• Macrobending loss in optical fibers offers a potential mechanism for displacement sensing.

Purpose of the Study:

• To design and demonstrate a multiple-arc optical fiber sensor for high-accuracy, large transient displacement measurement.
• To simplify the control of fiber curvature by relating it to linear deformation.
• To provide a method for controllable amplification of bending loss.

Main Methods:

• Designed a sensor by threading an optical fiber onto a soft, narrow plate to form multiple arcs.
• Controlled fiber curvature by manipulating the linear deformation of the plate.
• Tested the sensor by measuring the vibration of a cantilever beam.

Main Results:

• The optical fiber sensor demonstrated high accuracy in measuring large transient displacements.
• Achieved a sensitivity of 5.96 V/mm.
• Effectively captured detailed transient vibration characteristics of the cantilever beam.

Conclusions:

• The proposed threaded optical fiber sensor offers a simple manufacturing process and high performance.
• It is suitable for diverse environments requiring large dynamic displacement sensing.
• Provides a controllable method for amplifying bending loss for enhanced sensing capabilities.