Integrated FP/RFBG sensor with a micro-channel for dual-parameter measurement under high temperature

Area of Science:

• Optoelectronics
• Fiber Optics Sensing
• High-Temperature Instrumentation

Background:

• Traditional sensors face limitations in harsh, high-temperature environments.
• Accurate simultaneous measurement of multiple parameters like temperature, strain, and gas pressure is challenging.
• Integrated optical sensors offer potential for robust, multi-functional sensing.

Purpose of the Study:

• To develop and demonstrate an integrated sensor for simultaneous dual-parameter measurement.
• To achieve high sensitivity and accuracy for temperature, strain, and gas pressure sensing.
• To operate effectively under extreme high-temperature conditions (up to 600°C).

Main Methods:

• Fabrication of a micro Fabry-Perot (MFP) cavity on a regenerated fiber Bragg grating (RFBG) using micro-machining.
• Inscribing a fiber Bragg grating (FBG) and regenerating it to enhance strain sensitivity.
• Integrating a micro-channel on the MFP to significantly boost gas pressure sensitivity.

Main Results:

• The regenerated FBG demonstrated over three times enhanced strain sensitivity.
• The micro-channel integration improved MFP gas pressure sensitivity by nearly 100 times.
• The sensor successfully performed simultaneous measurements of high temperature and strain, and high temperature and gas pressure.

Conclusions:

• The integrated MFP-RFBG sensor offers a robust solution for dual-parameter sensing in high-temperature environments.
• The distinct sensitivities of MFP and RFBG enable selective measurement of different parameter combinations.
• This technology has potential applications in industrial process monitoring and harsh environment instrumentation.