Highly sensitive fiber optic temperature sensor based on a Solc-Sagnac interferometer with the harmonic Vernier...

Area of Science:

• Optoelectronics
• Fiber Optic Sensing
• Interferometry

Background:

• Accurate and rapid temperature monitoring is crucial for various engineering applications.
• Existing fiber optic temperature sensors often face trade-offs between sensitivity and response time.

Purpose of the Study:

• To propose and demonstrate a novel fiber optic temperature sensor (FOTS) with simultaneous high sensitivity and rapid response.
• To investigate the Vernier effect in a Solc-Sagnac interferometer for enhanced temperature sensing.

Main Methods:

• Utilized a compact Solc-Sagnac interferometer incorporating thin polarization-maintaining fibers (TPMFs).
• Implemented the Vernier effect by splicing TPMFs of specific lengths and angles.
• Configured different-order harmonic Vernier effects and employed an inner-envelope fitting technique.

Main Results:

• Demonstrated a distinct normal Vernier effect with a 45° splicing angle between TPMF fast axes.
• Achieved a temperature sensitivity of 27.12 nm/°C with the second-order Vernier effect.
• Showcased that sensitivity is proportional to harmonic order and inversely proportional to the detuning factor.

Conclusions:

• The developed FOTS offers high sensitivity, rapid response, simple structure, and excellent stability.
• The harmonic Vernier effect in a Solc-Sagnac interferometer is an effective method for high-performance temperature sensing.
• The FOTS holds significant potential for precise real-time temperature monitoring in demanding engineering applications.