Sensitivity-Improved Ultrasonic Sensor for 3D Imaging of Seismic Physical Model Using a Compact Microcavity

Area of Science:

• Optoelectronics
• Fiber Optics
• Acoustic Sensing

Background:

• Traditional ultrasonic sensors face limitations in sensitivity and size.
• Fiber-optic sensors offer potential for miniaturization and enhanced performance.
• Microcavity structures are explored for novel sensing applications.

Purpose of the Study:

• To propose and experimentally demonstrate a sensitivity-improved ultrasonic sensor.
• To investigate the role of hydrogen loading in hollow core fiber (HCF) for enhanced performance.
• To achieve high signal-to-noise ratio (SNR) for precise ultrasound detection.

Main Methods:

• Fabrication of a fiber-optic microcavity sensor by discharging a section of HCF.
• Hydrogen loading pretreatment of HCF to modify bubble formation characteristics.
• Utilizing Fabry-Perot interference within the microcavity for signal generation.
• Employing spectral side-band filtering technology for signal detection and image reconstruction.

Main Results:

• Successful formation of a fiber-optic microcavity with a compact air cavity.
• Achieved a high signal-to-noise ratio (SNR) of 69.28 dB.
• Demonstrated the ability to detect ultrasonic waves and reconstruct a 3D image of a seismic physical model (SMF).

Conclusions:

• The proposed hydrogen-loaded HCF microcavity sensor exhibits significantly improved sensitivity to ultrasound.
• The sensor design, leveraging Fabry-Perot interference and spectral filtering, enables high-fidelity ultrasound detection.
• This technology holds promise for advanced ultrasonic imaging and sensing applications.