Temperature-Decoupled Single-Crystal MgO Fiber-Optic Fabry-Perot Vibration Sensor Based on MEMS Technology for Harsh...

Area of Science:

• Materials Science
• Optical Engineering
• Sensor Technology

Background:

• High-temperature environments pose challenges for conventional sensor materials.
• Existing fiber-optic sensors often fail at extreme temperatures, limiting their application in industrial settings like aero-engines.

Purpose of the Study:

• To develop and demonstrate a high-temperature-resistance fiber-optic vibration sensor.
• To utilize magnesium oxide (MgO) for its superior thermal and optical properties in sensor construction.
• To address temperature cross-sensitivity for accurate vibration measurement.

Main Methods:

• Fabrication of an all-magnesium oxide (MgO) extrinsic Fabry-Perot interferometer (EFPI) sensor head using wet chemical etching and direct bonding.
• Implementation of a temperature decoupling method to isolate vibration signals from temperature fluctuations.
• Experimental validation of sensor performance at temperatures up to 1000 °C and vibration levels from 2-20 g.

Main Results:

• The MgO-based EFPI sensor demonstrated stable operation from 20 °C to 1000 °C.
• The sensor exhibited a sensitivity of 0.0073 rad at 20 °C.
• After temperature decoupling, the maximum nonlinearity error in vibration measurement was 1.17%.

Conclusions:

• A robust, high-temperature fiber-optic vibration sensor using MgO was successfully demonstrated.
• The developed sensor offers high temperature resistance and accurate dynamic performance.
• The sensor is suitable for demanding applications in testing aero-engines and gas turbine engines.