Product Code: ICA10_P134

Automatic Real-Time Guidance of Laser Machining with Inline Coherent Imaging
Authors:
Paul J. L. Webster, Department of Physics, Engineering Physics & Astronomy, Queens University at Kingston; Kingston ON Canada
Logan G. Wright, Department of Physics, Engineering Physics & Astronomy, Queens University at Kingston; Kingston ON Canada
Kevin D. Mortimer, Department of Physics, Engineering Physics & Astronomy, Queens University at Kingston; Kingston Canada
Ben Y. Leung, Department of Physics, Engineering Physics & Astronomy, Queens University at Kingston; Kingston ON Canada
Joe X. Z. Yu, Department of Physics, Engineering Physics & Astronomy, Queens University at Kingston; Kingston ON Canada
James M. Fraser, Department of Physics, Engineering Physics & Astronomy, Queens University at Kingston; Kingston ON Canada
Presented at ICALEO 2010

Optical coherence imaging can measure laser cut profiles in real-time (>300 kHz) without being blinded by intense machining light or incoherent plasma emissions. Rapid measurement of etch rate and stochastic behavior makes these images useful for process development and quality control in a variety of materials including metals, semiconductors and dielectrics. The ability to image through the ablation crater in materials transparent to infrared light allows the guidance of blind hole cutting even with limited a priori knowledge of the sample.

Significant improvement in hole depth accuracy with the application of manual feedback from this imaging has been previously demonstrated. However, the large volume of raw data and computing overhead are obstacles for the application of coherence imaging as a truly automatic feedback mechanism. Additionally, the high performance of coherent imaging systems adapted from biological imaging is costly and may be unnecessary for materials processing. In this work, we present a new low-cost coherent imaging system design and progress towards streamlining image processing for automated feedback.