Optical Strain Gauge Prototype Based on a High Sensitivity Balloon-like Interferometer and Additive Manufacturing.

Area of Science:

• Fiber optics
• Optical sensing
• Interferometry

Background:

• Traditional strain gauges can be limited by factors such as cost, size, and environmental sensitivity.
• Developing compact, cost-effective, and highly sensitive displacement sensors is crucial for structural health monitoring.

Purpose of the Study:

• To present and demonstrate a novel optical strain gauge based on a balloon-like interferometer structure.
• To evaluate the sensor's performance for displacement and strain measurements.

Main Methods:

• Fabrication of a balloon-like interferometer using a bent standard single-mode fiber and a 3D-printed component.
• Utilizing the interference between core and cladding modes induced by fiber curvature for sensing.
• Interrogating sensor response through wavelength shift or intensity change.

Main Results:

• The optical strain gauge demonstrated a sensitivity of 55.014 nm/mm for displacement measurements from 0 to 10 mm.
• A strain sensitivity of 500.13 pm/μϵ was achieved.
• The sensor exhibits a simple, compact design with easy fabrication and repeatability.

Conclusions:

• The developed optical strain gauge is a viable and cost-effective solution for measuring structure displacement.
• The sensor's performance characteristics make it suitable for various structural monitoring applications.
• The core-cladding mode interference principle offers a robust sensing mechanism.