Fiber optic fluorescence temperature sensors using up-conversion from rare-earth polymer composites

Area of Science:

• Materials Science
• Optical Sensors
• Nanotechnology

Background:

• Optical fiber sensors offer remote and multiplexed sensing capabilities.
• Rare-earth doped materials exhibit unique luminescent properties suitable for sensing applications.
• Developing robust and sensitive temperature probes remains crucial for various industrial and scientific fields.

Purpose of the Study:

• To demonstrate a novel optical fiber temperature sensor.
• To utilize the green up-conversion emission of rare-earth ions in a polymer matrix.
• To achieve accurate and stable temperature measurements using a fluorescent intensity ratio technique.

Main Methods:

• Fabrication of a temperature-sensitive composite by mixing NaY0.77Yb0.20Er0.03F4 rare-earth ions with polydimethylsiloxane polymer.
• Incorporation of the fluorescent composite material onto the tip of silica-glass optical fibers.
• Temperature measurement using the fluorescent intensity ratio (FIR) technique to analyze up-conversion emission.

Main Results:

• The developed fiber sensor exhibits good performance in the 20-100°C temperature range.
• The sensor demonstrates excellent linearity with an R-squared value of 0.999.
• The material shows good thermal and fluorescent stability, ensuring reliable measurements.

Conclusions:

• The polymer-based optical fiber sensor utilizing rare-earth up-conversion is a viable technology for accurate temperature sensing.
• The fluorescent intensity ratio method effectively minimizes signal interference and enhances measurement reliability.
• This sensor design offers a promising solution for point temperature monitoring with high stability and linearity.