Compact fiber biocompatible temperature sensor based on a hermetically-sealed liquid-filling structure

Area of Science:

• Optoelectronics
• Fiber optics
• Sensor technology

Background:

• Accurate temperature sensing is crucial in various fields, including biological applications.
• Traditional fiber optic sensors often face limitations in cost, sensitivity, or operating temperature range.

Purpose of the Study:

• To develop a compact, robust, and cost-effective fiber optic temperature sensor.
• To leverage the properties of ethanol for enhanced temperature sensitivity and sub-zero detection.
• To explore the potential of this sensor for biological applications.

Main Methods:

• Fabrication of a hermetically-sealed liquid-filling Fabry-Perot (FP) cavity using fusion splicing, liquid injection, and fused tapering.
• Utilizing ethanol as the sensing medium due to its high thermal optical coefficient (TOC) and low freezing point.
• Characterization of the sensor's performance, including sensitivity, response time, repeatability, and stability.

Main Results:

• Achieved a linear sensitivity of 429 pm/°C in the temperature range of -5 °C to 30 °C.
• Demonstrated the capability to detect sub-zero temperatures owing to ethanol's low freezing point.
• Exhibited rapid response time, good repeatability, and excellent stability.

Conclusions:

• The developed fiber optic temperature sensor offers a cost-effective and high-performance solution.
• Its biocompatible structure and ability to measure sub-zero temperatures make it promising for biological applications.
• The sensor's design and performance highlight advancements in fiber optic sensing technology.