Batch-producible MEMS fiber-optic Fabry-Perot pressure sensor for high-temperature application.

Area of Science:

• Optoelectronics
• Materials Science
• Sensor Technology

Background:

• High-temperature pressure sensing is critical in various industrial applications.
• Existing sensors often face challenges with accuracy and durability at elevated temperatures.
• Micro-electro-mechanical systems (MEMS) offer miniaturization and integration potential for sensor design.

Purpose of the Study:

• To develop and demonstrate a robust fiber-optic Fabry-Perot pressure sensor for high-temperature environments.
• To achieve accurate pressure measurements through effective temperature compensation.
• To leverage batch fabrication for cost-effective and uniform sensor production.

Main Methods:

• Fabrication of sensing heads using anodic bonding of Pyrex glass and gold-plated silicon wafers.
• Formation of the Fabry-Perot cavity by fusing the sensing head and single-mode fiber with CO2 laser.
• Integration of a fiber Bragg grating for simultaneous temperature measurement and decoupling.

Main Results:

• The developed sensor exhibits a maximum nonlinearity of 0.4%.
• After temperature decoupling, the sensor shows a maximal error of less than 1.05% for pressures up to 0.5 MPa.
• Performance was validated across a temperature range of 20°C to 350°C.

Conclusions:

• The fiber-optic Fabry-Perot pressure sensor is suitable for reliable high-temperature applications.
• The temperature decoupling method significantly improves measurement accuracy.
• Batch fabrication ensures low cost and high uniformity, enabling practical deployment.