Authors: Sonny Ly, Gabe Guss, Alexander M. Rubenchik, Wesley J. Keller, Nan Shen, Raluca A. Negres, Jeff Bude, Lawrence Livermore National Laboratory
The research team at Lawrence Livermore National Laboratory has studied how melt pool dynamics, droplet ejections and hole drilling are influenced by periodically modulated laser intensity.
The researchers used ultra-high speed imaging to reveal that melt pool oscillations, when excited at the natural oscillation frequency, can drive larger removal of material.
Figure 1 shows laser hole drilling with sinusoidal power modulation at 8khz, near the peak of the resonance.
Detailed explanation of the removal effects at different modulation can be found in Nature Scientific Reports 9, Article number: 8152 (2019) under the title “Resonance excitation of surface capillary waves to enhance material removal for laser material processing”. The article can be found from: https://www.nature.com/articles/s41598-019-44577-6.
Ablation Laser: 1064nm, 600 W power stationary beam
Camera: 100 kfps
Illumination: CAVILUX HF with 100ns pulse length
Camera up to 100 kfps: Photron SA-X2
Camera up to 1 Mfps: Shimadzu HPV-2
Illumination: CAVILUX HF System by Cavitar
Sonny Ly, Gabe Guss, Alexander M. Rubenchik,
Wesley Keller, Nan Shen, Raluca A. Negres,
Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE-AC52-07NA27344