Analysis of a fiber specklegram sensor by using coupled-mode theory

Area of Science:

• Optical sensing technologies
• Fiber optic sensors
• Waveguide theory

Background:

• Fiber specklegram sensors (FSS) offer unique sensing capabilities.
• Understanding the factors influencing FSS performance is crucial for optimizing sensor design.
• Microbending effects are a key consideration in fiber optic sensor analysis.

Purpose of the Study:

• To analyze the performance of fiber specklegram sensors (FSS) using waveguide coupled-mode theory.
• To investigate the impact of microbending on FSS sensitivity.
• To determine how core diameter and bending geometry influence FSS performance.

Main Methods:

• Theoretical analysis based on waveguide coupled-mode theory.
• Modeling the microbending effect on the sensing fiber.
• Experimental validation of theoretical predictions.

Main Results:

• FSS sensitivity is significantly affected by the fiber's core diameter.
• Bending geometry plays a critical role in determining FSS sensitivity.
• Experimental data strongly correlate with the theoretical analyses.

Conclusions:

• The study provides a theoretical framework for understanding FSS performance under microbending.
• Core diameter and bending geometry are identified as key design parameters for FSS.
• The findings are experimentally validated, confirming the analytical model's accuracy.