Miniature high-sensitivity high-temperature fiber sensor with a dispersion compensation fiber-based interferometer

Area of Science:

• Optoelectronics and Photonics
• Fiber Optic Sensing Technology
• Materials Science for High-Temperature Applications

Background:

• Accurate high-temperature monitoring is crucial in various industrial and scientific fields.
• Traditional fiber optic sensors often face limitations in sensitivity, size, or operating temperature range.
• Interferometric fiber sensors offer potential for enhanced performance but require optimized configurations.

Purpose of the Study:

• To develop a miniature, high-sensitivity fiber optic sensor capable of operating at high temperatures.
• To investigate the use of a bare small-core-diameter dispersion compensation fiber (DCF) as a sensing element.
• To achieve a cost-effective and structurally simple high-temperature sensing solution.

Main Methods:

• Fabrication of a sensing head using a 4 mm long bare DCF fused to a single-mode fiber (SMF).
• Utilizing the inherent properties of DCF, including a large mode index difference and high thermo-optic coefficient.
• Monitoring the wavelength shift of the interference spectrum generated within the DCF interferometer.

Main Results:

• A miniature fiber sensor with a high sensitivity of 68.6 pm/°C was successfully demonstrated.
• The sensor leverages two dominant interference modes within the DCF for enhanced signal response.
• The developed sensor exhibits small size, high sensitivity, stability, and a simple, low-cost structure.

Conclusions:

• A novel miniature fiber optic sensor based on a bare DCF interferometer is effective for high-temperature sensing.
• The sensor's design offers a significant improvement in sensitivity and operational characteristics.
• This technology presents a promising, cost-effective solution for demanding high-temperature measurement applications.