In situ 24 kHz coherent imaging of morphology change in laser percussion drilling.
We observe sample morphology changes in real time (24 kHz) during and between percussion drilling pulses by integrating a low-coherence microscope into a laser micromachining platform. Nonuniform cut speed and sidewall evolution in stainless steel are observed to strongly depend on assist gas. Interpulse morphology relaxation such as hole refill is directly imaged, showing dramatic differences in the material removal process dependent on pulse duration/peak power (micros/0.1 kW, ps/20 MW) and material (steel, lead zirconate titanate PZT). Blind hole depth precision is improved by over 1 order of magnitude using in situ feedback from the imaging system.
Webster
Paul J L
PJ
Department of Physics, Engineering Physics and Astronomy, Queen's University, Kingston, Canada K7L 3N6. webster@physics.queensu.ca
Yu
Joe X Z
JX
Leung
Ben Y C
BY
Anderson
Mitchell D
MD
Yang
Victor X D
VX
Fraser
James M
JM
D007834:Lasers; D008422:Materials Testing / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D013193:Stainless Steel / Q000737:chemistry* / Q000528:radiation effects*; D013499:Surface Properties; D041623:Tomography, Optical Coherence / Q000379:methods*
D013193:Stainless Steel