Wide-range optical fiber temperature sensor based on up-conversion luminescent nanocrystals.

Area of Science:

• Materials Science
• Optical Engineering
• Nanotechnology

Background:

• Accurate temperature sensing is critical in various demanding environments, including aerospace.
• Traditional sensors may face limitations in extreme temperature ranges or require complex infrastructure.
• Up-conversion luminescence (UCL) offers a promising alternative for optical sensing applications.

Purpose of the Study:

• To develop and characterize a novel optical fiber temperature sensor.
• To utilize up-conversion luminescence (UCL) materials for enhanced sensing performance.
• To evaluate the sensor's suitability for wide-range temperature measurements, particularly in aerospace.

Main Methods:

• Fabrication of a sensing unit using sodium yttrium fluoride (NaYF4): ytterbium (Yb3+), erbium (Er3+) nanocrystals.
• Integration of the sensing unit into an optical fiber using fiber fusion technology.
• Experimental characterization of the sensor's spectral response across a temperature range of 80-373 K.

Main Results:

• The optical fiber temperature sensor exhibited significant spectrum-temperature characteristics within the 80-373 K range.
• Achieved relative sensitivities of 2.2×10⁻³/K (R²=0.957) at low temperatures and 9.1×10⁻³/K (R²=0.994) at normal temperatures.
• Demonstrated good mechanical strength and system stability.

Conclusions:

• The proposed UCL-based optical fiber temperature sensor is effective for wide-range temperature measurements.
• The sensor's high sensitivity, stability, and mechanical strength indicate significant potential for aerospace applications.
• Further development could lead to robust temperature monitoring solutions for environments with large temperature differentials.