Microwave photonic filter-based interrogation system for multiple fiber Bragg grating sensors.

Area of Science:

• Optoelectronics
• Fiber Optics
• Sensor Technology

Background:

• Fiber Bragg gratings (FBGs) are sensitive to environmental changes, making them suitable for condition monitoring.
• Interrogating multiple FBGs typically requires complex systems.

Purpose of the Study:

• To propose and demonstrate a new technique for interrogating multiple FBG sensors.
• To enable simultaneous and independent multi-point sensing using a single system.

Main Methods:

• Utilizing the spectrum-slicing properties of FBG Fabry-Perot cavities to create a double passband microwave photonic (MWP) filter.
• Tracking temperature-induced shifts in MWP filter passbands by monitoring detected power at a fixed radio frequency.
• Employing a ratiometric approach to enhance sensitivity and analyzing cross-talk for multi-sensor operation.

Main Results:

• Demonstrated a technique for interrogating multiple FBG sensors.
• Successfully monitored local temperatures at two distinct locations simultaneously and independently.
• Showcased the feasibility of a single measurement system for multi-point sensing.

Conclusions:

• The proposed MWP filtering technique offers an effective solution for simultaneous multi-sensor interrogation.
• This method provides a robust platform for distributed temperature sensing applications.
• The approach enhances the efficiency and practicality of FBG-based condition monitoring.