A Large-Range and High-Sensitivity Fiber-Optic Fabry-Perot Pressure Sensor Based on a Membrane-Hole-Base Structure

Area of Science:

• Materials Science
• Optical Engineering
• Sensor Technology

Background:

• Fiber-optic Fabry-Perot pressure sensors are valuable for in situ high-temperature measurements due to their size and robustness.
• Existing sensors face challenges including complex fabrication, limited measurement ranges, and insufficient sensitivity.

Purpose of the Study:

• To develop an advanced fiber-optic Fabry-Perot pressure sensor with enhanced performance.
• To address the limitations of current sensors in terms of sensitivity, range, and environmental resistance.

Main Methods:

• Fabrication of the sensor's sensitive core using laser cutting and direct bonding of three-layer sapphire.
• Development of a specialized demodulation algorithm for the large-cavity-length Fabry-Perot cavity.
• Integration of a membrane-hole-base structure for improved sensing capabilities.

Main Results:

• The developed sensor demonstrates significantly enhanced sensitivity (918.9 nm/MPa).
• Achieved a wide pressure sensing range of 0-10 MPa across temperatures from 20-370 °C.
• Exhibited excellent stability with a temperature coefficient of 0.0695 nm/(MPa∙°C) and a full-range error below 2.312%.

Conclusions:

• The proposed membrane-hole-base fiber-optic Fabry-Perot pressure sensor offers a simplified structure and convenient preparation.
• The sensor exhibits superior pressure resistance, anti-harsh environment capabilities, and large-range sensing performance.
• This technology represents a significant advancement for in situ high-temperature pressure measurement applications.