High-Temperature-Resistant Fiber Laser Vector Accelerometer Based on a Self-Compensated Multicore Fiber Bragg...

Area of Science:

• Photonics and Sensing Technologies
• Fiber Optic Sensors
• Instrumentation Engineering

Background:

• Traditional accelerometers face limitations in high-temperature and harsh environments.
• Need for robust sensors capable of measuring vector acceleration with high accuracy.
• Fiber optic sensing offers potential for extreme condition applications.

Purpose of the Study:

• To propose and demonstrate a novel high-temperature-resistant vector accelerometer.
• To enable simultaneous measurement of vibration orientation and acceleration.
• To assess sensor performance under extreme temperature and strain conditions.

Main Methods:

• Utilized a ring cavity laser as the light source.
• Inscribed fiber Bragg gratings (FBGs) in a seven-core fiber (SCF) using femtosecond laser direct writing.
• Employed three FBGs with 120° angular separation for vector sensing and a central FBG as a reflector.

Main Results:

• Achieved a working frequency bandwidth of 4 to 68 Hz.
• Demonstrated a maximum sensitivity of 54.2 mV/g and azimuthal angle accuracy of 0.21°.
• Exhibited stable signal-to-noise ratio (SNR) with minimal fluctuation (~1 dB) across a wide temperature (50 °C to 1050 °C) and strain (0 to 2289 με) range.

Conclusions:

• The developed vector accelerometer is suitable for operation in harsh environments, including aerospace and nuclear reactors.
• The sensor design effectively mitigates external interference from temperature and strain fluctuations.
• This technology offers a promising solution for advanced vibration monitoring applications.