Microwave photonics interrogation for multiplexing fiber Fabry-Perot sensors

Area of Science:

• Photonics
• Optical Sensing
• Microwave Engineering

Background:

• Fiber Fabry-Perot (FP) sensors are crucial for environmental monitoring.
• Existing demodulation schemes face limitations with short-cavity FP sensors in quasi-distributed networks.
• Hollow core fiber (HCF) based FP sensors offer unique properties for sensing applications.

Purpose of the Study:

• To demonstrate a microwave photonics interrogation system for multiplexing short-cavity FP sensors.
• To enable quasi-distributed sensing networks with enhanced interrogation capabilities.
• To analyze the system's performance and theoretical limits.

Main Methods:

• Utilizing a dispersion element to convert superimposed reflected spectra into frequency-domain passbands.
• Employing microwave photonics for signal processing and demodulation.
• Conducting experimental validation and numerical studies.

Main Results:

• Achieved high linearity and interrogation ability in both all-FP and hybrid multiplexing systems.
• Demonstrated strain sensitivity of 0.938 kHz/µɛ and temperature sensitivity of -0.699 MHz/°C.
• Realized a FP cavity length demodulation sensitivity of 1.563 MHz/µm.

Conclusions:

• The developed microwave photonics system effectively interrogates multiplexed short-cavity FP sensors.
• The system shows significant potential for quasi-distributed sensing networks.
• Numerical studies provide insights into system optimization and capacity.