Durability Optimization of Fiber Grating Hydrogen Sensor Based on Residual Stress

Area of Science:

• Materials Science
• Optical Engineering
• Chemical Sensing

Background:

• Optical fiber grating (OFG) hydrogen sensors offer high sensitivity but often suffer from durability issues.
• Improving the long-term stability and reliability of OFG hydrogen sensors is crucial for practical applications.

Purpose of the Study:

• To enhance the durability, precision, and stability of optical fiber grating hydrogen sensors.
• To determine the optimal coating parameters for sensor fabrication using finite element analysis.

Main Methods:

• Simplified two-dimensional modeling and finite element analysis (FEA) were employed.
• The study investigated the impact of film thickness, coating speed, and coating times on residual stress.
• FEA results were validated through hydrogen sensitivity and durability testing.

Main Results:

• Residual stress increased with film thickness up to 150 nm; stability was observed between 200-250 nm.
• Coating speed showed minimal effect on residual stress.
• Optimal parameters were identified as 200 nm thickness, 62.5 μm/s speed, and three coating times, yielding the lowest stress.

Conclusions:

• Optimized coating parameters significantly improve the durability and stability of OFG hydrogen sensors.
• FEA is a reliable tool for predicting and optimizing sensor fabrication processes.
• The developed sensor exhibits high precision, stability, and durability for hydrogen detection.