Melt dynamics of aluminum irradiated with ultrafast laser radiation at large intensities

Journal Article · Wed Jul 01 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3159882· OSTI ID:21359283

Mingareev, Ilya ^[1]; Horn, Alexander ^[2]

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1. Lehrstuhl fuer Lasertechnik, RWTH Aachen University, 52074 Aachen (Germany)
2. Institute of Physics and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, 34132 Kassel (Germany)

Ablation of bulk aluminum has been investigated in situ using ultrafast laser radiation produced by chirped-pulse amplification technique (t{sub p}=80 fs, lambda=800 nm). Melt dynamics and the contribution of the amplified spontaneous emission (ASE) to the ablation have been studied experimentally and numerically for laser fluences well above ablation threshold (F < or approx. 10{sup 3}xF{sub thr}). Using transient quantitative phase microscopy (TQPm), dimensions and volume of ejected vapor, melt droplets, and liquid jets has been investigated. Computational analysis of the optical phase images has been used to determine the total volume of ejected material. A series of time-resolved phase images of vaporized material and/or melt, which are induced by n=1.8 pulses on an aluminum target, are obtained by means of TQPm up to temporal delay tau=1.65 mus after irradiation. Increase in material ejection rate is observed at delays tauapprox =300 ns and tauapprox =1.1 mus after the incident pulse. For large irradiation intensities a considerable contribution of ASE to ablation dynamics has been detected. Ex situ measurements of the ablated material by means of white-light interferometry and scanning electron microscopy provides corresponding factual removed volumes and highlight the pulse-to-pulse morphology changes.

• OSTI ID: 21359283
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 1; Other Information: DOI: 10.1063/1.3159882; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABLATION
ALUMINIUM
DROPLETS
INTERFEROMETRY
LASER RADIATION
LIQUID METALS
MORPHOLOGY
PULSES
SCANNING ELECTRON MICROSCOPY
SUPERRADIANCE
TIME RESOLUTION
VAPORS
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
ELEMENTS
EMISSION
ENERGY-LEVEL TRANSITIONS
FLUIDS
GASES
LIQUIDS
METALS
MICROSCOPY
PARTICLES
PHOTON EMISSION
RADIATIONS
RESOLUTION
STIMULATED EMISSION
TIMING PROPERTIES