Highly Integrated All-Fiber FP/FBG Sensor for Accurate Measurement of Strain under High Temperature

Area of Science:

• Materials Science
• Optical Engineering
• Sensor Technology

Background:

• Accurate strain and pressure measurement is critical in high-temperature environments.
• Existing sensors often face limitations in harsh conditions, necessitating advanced solutions.

Purpose of the Study:

• To develop and demonstrate a highly integrated all-fiber sensor for precise dual-parameter measurement (strain/high-pressure) in high-temperature environments.
• To leverage the complementary characteristics of fiber Bragg gratings (FBGs) and micro extrinsic Fabry-Perot (FP) cavities for enhanced sensing capabilities.

Main Methods:

• Fabrication of a cascaded sensor combining a fiber Bragg grating (FBG) inscribed by an 800 nm femtosecond laser with a micro extrinsic Fabry-Perot (FP) cavity created using 157 nm laser micromachining.
• Utilizing the differential sensitivities of FBG (temperature) and FP (strain/pressure) components for dual-parameter sensing.

Main Results:

• The proposed sensor demonstrated good strain measurement characteristics at high temperatures.
• Excellent high-pressure performance was observed at room temperature.
• The device exhibits a highly sensitive wavelength response suitable for harsh environment applications.

Conclusions:

• The developed cascaded FBG-FP all-fiber sensor is effective for dual-parameter measurement in high-temperature and high-pressure conditions.
• This sensor technology holds significant potential for applications in harsh industrial and scientific environments requiring precise monitoring.