Ultrasonic noncontact inspection system with optical fiber methods

Area of Science:

• Materials Science
• Optics and Photonics
• Non-Destructive Testing

Background:

• Noncontact laser-ultrasound techniques are increasingly important for material inspection.
• Practical application requires overcoming challenges in ultrasound generation and detection.
• Optimizing beam direction and focusing is crucial for sensitive defect detection.

Purpose of the Study:

• To develop and evaluate advanced laser-based ultrasound techniques for material inspection.
• To improve sensitivity and control in noncontact ultrasound generation and detection.
• To facilitate remote and scanned inspection of materials.

Main Methods:

• Development of a fiber-optic phase array for controlled ultrasound generation.
• Comparison of various optical ultrasound detection techniques.
• Implementation of a confocal Fabry-Perot interferometer system for detection.
• Integration of a multimode fiber for remote sensing capabilities.

Main Results:

• The fiber-optic phase array allows for controlled beam direction and focusing of generated ultrasound.
• The confocal Fabry-Perot interferometer system demonstrates superior performance for ultrasound detection, especially on diffusely reflecting surfaces.
• The integrated multimode fiber enables flexible, remote, and scanned inspection.

Conclusions:

• The developed fiber-optic phase array and confocal Fabry-Perot interferometer system significantly enhance noncontact ultrasound-based material inspection.
• These advancements improve defect detection sensitivity and enable versatile inspection scenarios.
• The system is well-suited for practical inspection tasks requiring remote and scanned detection.