Experimental study of a tapered fiber temperature sensor with a liquid seal based on multimode interference

Area of Science:

• Optics and Photonics
• Materials Science
• Sensor Technology

Background:

• High-precision temperature measurement is critical across various scientific and industrial fields.
• Existing fiber-optic temperature sensors face limitations in sensitivity and operational range.
• Developing advanced sensing materials and structures is key to overcoming these challenges.

Purpose of the Study:

• To investigate a novel liquid-sealed multimode interference fiber temperature sensor with a double-taper structure.
• To experimentally analyze the impact of structural design and sealed-liquid properties on temperature sensitivity.
• To optimize sensor performance for high-precision temperature measurement applications.

Main Methods:

• Fabrication of a liquid-sealed fiber-optic temperature sensor incorporating a double-taper structure.
• Systematic experimental analysis of sensor performance with varying sealed-liquid materials and refractive indices.
• Characterization of temperature sensitivity and failure temperature under different conditions.

Main Results:

• The double-taper structure significantly enhances the temperature sensitivity of the fiber-optic sensor.
• Increased refractive index of the sealed liquid directly correlates with improved temperature sensitivity.
• An ultra-high temperature sensitivity of -8.28 nm/K was achieved near the sensor's failure temperature.
• Beyond a certain refractive index, further increases in sealed liquid index yield diminishing returns in sensitivity.

Conclusions:

• The proposed liquid-sealed fiber-optic temperature sensor demonstrates superior performance for high-precision measurements.
• Structural optimization and judicious selection of sealed-liquid materials are crucial for maximizing sensor sensitivity.
• This research provides a foundation for developing next-generation high-precision temperature-sensing systems.