Automatic laser welding and milling with in situ inline coherent imaging

Area of Science:

• Optical Engineering
• Materials Science
• Biotechnology

Background:

• High-power lasers offer versatile processing but face depth control challenges.
• Accurate measurement of laser penetration depth is critical for precision applications.

Purpose of the Study:

• To demonstrate inline coherent imaging (ICI) for direct measurement of laser penetration depth.
• To enable automatic, adaptive control of laser-based material processing.
• To achieve high-resolution 3D sculpting in heterogeneous materials.

Main Methods:

• Utilized inline coherent imaging (ICI) with high line rates (up to 312 kHz) and microsecond capture times.
• Applied ICI to measure laser penetration depth during high-power (kW-class) keyhole welding.
• Leveraged ICI's high dynamic range and optical interference robustness.

Main Results:

• Directly measured laser penetration depth in real-time during aggressive laser processes.
• Achieved automatic, adaptive control for laser welding and ablation processes.
• Demonstrated 3D micron-scale sculpting capabilities in diverse biological materials.

Conclusions:

• ICI is a viable technique for precise depth control in high-power laser processing.
• The high-speed, robust nature of ICI enables adaptive control systems.
• ICI facilitates advanced manufacturing and scientific research requiring micron-scale precision.