A novel method is presented for determining the volume of molten material ejected from a substrate as a result of visible pulsed-laser ablation. A 100-µm-wide pulsed-laser light sheet (τ ∼ 5 ns, λ = 532 nm) was used in conjunction with a CCD camera to provide high-speed cross-sectional images of single-pulse ablation of aluminum with a visible nanosecond laser source. Computational analysis of the two-dimensional gray-scale images was used to determine the total volume of material ejected from the substrate in the form of molten droplets. Ablation with dual-wavelength (511- and 578-nm) pulses of 30-ns duration was characterized under various fluence conditions (0–25 J cm-2), allowing a quantitative threshold for explosive melt ejection in aluminum to be established at ∼10 J cm-2. The temporal evolution of the ejected material showed that, for an incident fluence of ∼40 J cm-2, molten-droplet ejection commenced at ∼400 ns and ceased after ∼2 µs.
© 2004 Optical Society of AmericaFull Article | PDF Article
Joseph P. Cummings and Joseph T. Walsh
Appl. Opt. 32(4) 494-503 (1993)
Gavin A. J. Markillie, Howard J. Baker, Francisco J. Villarreal, and Denis R. Hall
Appl. Opt. 41(27) 5660-5667 (2002)
Stéphanie Palmier, Jean Luc Rullier, Jérémie Capoulade, and Jean Yves Natoli
Appl. Opt. 47(8) 1164-1170 (2008)