A high sensitive fiber-optic strain sensor with tunable temperature sensitivity for temperature-compensation...

Area of Science:

• Optoelectronics
• Materials Science
• Mechanical Engineering

Background:

• Strain sensors are crucial for structural health monitoring and material analysis.
• Existing sensors often face challenges with temperature sensitivity and detection limits.
• The need for high-sensitivity, temperature-compensated strain measurement persists.

Purpose of the Study:

• To propose and demonstrate a high-sensitivity fiber-optic strain sensor.
• To achieve tunable temperature sensitivity for improved accuracy.
• To enable precise strain detection for various applications, including thermal expansion compensation.

Main Methods:

• A sensor design incorporating a cantilever, tandem rod, and fiber collimator was developed.
• The tandem rod's length ratio was adjusted to tune temperature sensitivity.
• Incident-angle sensitive detection was employed, leveraging the collimator's low beam divergence.

Main Results:

• Tunable temperature sensitivity ranging from -0.15 to 0.19 dB/°C was achieved.
• A high strain sensitivity was realized through the incident-angle detection mechanism.
• Demonstrated strain detection range of 1.1 × 10³ με (21.5 mm sensing length), detection limit of 5.7 × 10⁻³ με, and max operating frequency of 1.18 KHz.

Conclusions:

• The proposed fiber-optic strain sensor exhibits high sensitivity and tunable temperature compensation.
• The sensor's performance makes it suitable for accurate strain monitoring.
• It holds promise for compensating thermal expansion in diverse target objects.