In-fiber integrated high sensitivity temperature sensor based on long Fabry-Perot resonator

Area of Science:

• Optoelectronics
• Fiber Optics Sensors
• Metrology

Background:

• Traditional temperature sensors often lack the sensitivity and stability required for demanding high-temperature environments.
• Fiber optic sensors offer advantages in harsh conditions, but enhancing their sensitivity remains a key challenge.

Purpose of the Study:

• To develop and demonstrate a novel in-fiber integrated high-sensitivity temperature sensor.
• To achieve enhanced sensitivity through the use of a long Fabry-Perot (FP) resonator.

Main Methods:

• Constructed an FP resonator within a quartz capillary using two single-mode fibers (SMFs) with gold-coated end faces.
• Employed a white light interference demodulation system to measure FP cavity length variations.
• Utilized multiple light reflections within the FP cavity to multiply sensor sensitivity.

Main Results:

• The sensor successfully measured temperatures up to 350°C over a 2-hour period.
• Achieved a sensitivity six times greater than traditional interference temperature sensors.
• Demonstrated the effectiveness of the FP resonator for enhanced temperature sensing.

Conclusions:

• The developed in-fiber FP resonator temperature sensor offers high sensitivity and stability.
• Its low cost, simple fabrication, and high performance make it suitable for widespread use in high-temperature applications.
• This technology represents a significant advancement in optical temperature sensing.