Distributed strain sensor based on dynamic grating in polarization-maintaining erbium-doped fiber

Area of Science:

• Photonics and Optical Sensing
• Fiber Optic Sensors
• Materials Science

Background:

• Distributed fiber-optic sensing offers real-time monitoring capabilities.
• Polarization-maintaining fibers are crucial for stable optical measurements.
• Dynamic gratings enable localized sensing within optical fibers.

Purpose of the Study:

• To demonstrate a novel distributed fiber-optic strain sensor.
• To utilize dynamic gratings in polarization-maintaining erbium-doped fiber (PM-EDF).
• To achieve high spatial resolution for strain localization.

Main Methods:

• Writing dynamic gratings using polarized light beams along orthogonal axes of PM-EDF.
• Reading gratings with light polarized along the other axis.
• Employing synthesis of optical coherence function for grating localization.
• Measuring Bragg reflection frequency shifts proportional to strain-induced birefringence changes.

Main Results:

• Successful experimental demonstration of the novel distributed strain sensor.
• Strain application directly correlates with shifts in Bragg reflection frequency.
• Localization technique allows sweeping the sensing region along the fiber.
• Achieved a spatial resolution of 20 cm for strain detection.

Conclusions:

• The developed sensor effectively measures distributed strain using dynamic gratings in PM-EDF.
• The technique provides a localized and precise method for strain monitoring.
• This technology has potential applications in structural health monitoring and other fields requiring precise strain measurement.