Sapphire optical fiber high-temperature vibration sensor.

Area of Science:

• Materials Science
• Optical Engineering
• Sensor Technology

Background:

• High-temperature environments pose significant challenges for conventional vibration sensors.
• Existing sensors often fail or degrade under extreme thermal conditions.
• There is a need for robust sensors capable of accurate measurement in harsh industrial settings.

Purpose of the Study:

• To propose and demonstrate a novel sapphire fiber extrinsic Fabry-Perot interferometer (EFPI) sensor.
• To evaluate the sensor's performance for high-temperature vibration measurements.
• To provide a feasible solution for vibration monitoring in extreme environments.

Main Methods:

• Fabrication of a vibrating diaphragm using femtosecond laser etching on a sapphire wafer.
• Construction of an EFPI cavity using the sapphire fiber end face and the diaphragm.
• Signal acquisition via sapphire fiber and demodulation using laser interferometry.
• Experimental testing across a range of temperatures and accelerations.

Main Results:

• Demonstrated linear acceleration response from 0-10 g with a sensitivity of 20.91 nm/g.
• Achieved a resonance frequency of 2700 Hz, validated by ANSYS simulations.
• Confirmed operational capability from room temperature up to 1500 °C.

Conclusions:

• The developed sapphire fiber EFPI sensor is suitable for high-temperature vibration measurements.
• The sensor exhibits excellent linearity, sensitivity, and high-temperature resistance.
• This technology offers a promising approach for vibration monitoring in extreme thermal environments.