Research on sensitized Fiber Bragg Grating temperature sensor based on bimetal three-substrates.

Area of Science:

• Geophysics and seismology
• Materials science and engineering
• Optical sensing technologies

Background:

• Temperature is a critical parameter in monitoring earthquake precursors.
• Existing Fiber Bragg Grating (FBG) temperature sensors suffer from low sensitivity, limiting their application in precise precursor observation.

Purpose of the Study:

• To develop a sensitized FBG temperature sensor with enhanced sensitivity for earthquake precursor observation.
• To address the limitations of low sensitivity in conventional FBG temperature sensors.

Main Methods:

• Theoretical analysis of a bimetallic model to optimize sensor structural parameters.
• Finite element analysis (FEA) using ANSYS for sensor simulation and validation.
• Fabrication of the sensitized sensor based on simulation results.
• Performance testing using a dedicated temperature test system.

Main Results:

• The developed sensitized FBG temperature sensor exhibits a sensitivity of 49.3 pm/°C.
• Achieved sensitivity is approximately 4.9 times higher than that of a bare FBG sensor.
• The sensor demonstrates excellent linearity with a correlation coefficient exceeding 0.999.

Conclusions:

• The proposed bimetal three-substrate FBG temperature sensor significantly improves sensitivity for earthquake precursor monitoring.
• The research provides a valuable reference for developing high-sensitivity FBG temperature sensors.
• Optimized structural parameters and simulation-driven design are key to enhancing sensor performance.