Temperature-insensitive simultaneous rotation and displacement (bending) sensor based on tilted fiber Bragg grating.

Area of Science:

• Optoelectronics
• Fiber Optic Sensors
• Metrology

Background:

• Accurate measurement of multi-dimensional physical parameters is crucial in various engineering fields.
• Traditional sensing methods often require multiple sensors or are sensitive to environmental factors.
• Fiber Bragg gratings offer a robust platform for sensing applications.

Purpose of the Study:

• To develop a single tilted fiber Bragg grating (TFBG) based system for simultaneous measurement of rotation and displacement or bending.
• To demonstrate the system's insensitivity to temperature variations and fiber stretching direction.
• To showcase the versatility and tunable measurement range of the proposed sensing approach.

Main Methods:

• Utilizing a single tilted fiber Bragg grating (TFBG) as the core sensing element.
• Implementing a measurement setup to induce and quantify rotation, displacement, and bending.
• Analyzing the spectral response of the TFBG to determine the sensitivities for each parameter.

Main Results:

• Simultaneous measurement of rotation and displacement/bending achieved using a single TFBG.
• Demonstrated insensitivity to temperature changes and fiber stretching direction.
• Experimentally determined sensitivities: -0.0018 1/deg. (rotation), 0.0054 nm/mm (displacement), and -0.055 1/mm (bending).
• Tunable measurement ranges by adjusting the fiber-loop radius.

Conclusions:

• The proposed TFBG-based system offers a versatile and robust solution for simultaneous multi-parameter sensing.
• The ability to tune the measurement range enhances its applicability in diverse scenarios.
• This method provides a cost-effective and efficient alternative for structural health monitoring and robotics.