Ablation Process (ablation + process)

Distribution by Scientific Domains


Selected Abstracts


Cover Picture: Laser & Photon.

LASER & PHOTONICS REVIEWS, Issue 5 2009
Rev. 3(5)/200
Ablation impact of a spherical polystyrene particle on a silicon surface irradiated with single femtosecond pulses. The anisotropy is a result of the near-field-enhanced sub-threshold ablation process. (Picture: A. Plech, P. Leiderer, J. Boneberg, pp. 435,451, in this issue) [source]


Femtosecond laser ablation elemental mass spectrometry

MASS SPECTROMETRY REVIEWS, Issue 4 2006
Roland Hergenröder
Abstract Laser ablation mass spectrometry (LA-MS) has always been an interesting method for the elemental analysis of solid samples. Chemical analysis with a laser requires small amounts of material. Depending on the analytical detection system, subpicogram quantities may be sufficient. In addition, a focused laser beam permits the spatial characterization of heterogeneity in solid samples typically with micrometer resolution in terms of lateral and depth dimensions. With the advent of high-energy, ultra-short pulse lasers, new possibilities arise. The task of this review is to discuss the principle differences between the ablation process of short (>1 ps) and ultra-short (<1 ps) pulses. Based on the timescales and the energy balance of the process that underlies an ablation event, it will be shown that ultra-short pulses are less thermal and cause less collateral damages than longer pulses. The confinement of the pulse energy to the focal region guarantees a better spatial resolution in all dimensions and improves the analytical figures of merit (e.g., fractionation). Applications that demonstrate these features and that will be presented are in-depth profiling of multi-layer samples and the elemental analysis of biological materials. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 25:551,572, 2006 [source]


The age of the Geminids: a constraint from the spin-up time-scale

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2002
Martin Beech
Abstract Interpreting fireball flickering in terms of the rotational modulation of the ablation process, the time since ejection into space of three Geminid meteoroids is determined. By estimating the time required to spin-up a meteoroid through non-isotropic photon scattering interactions with the solar radiation field, we find meteoroid ages consistent with ejection times some 1000,4000 yr ago. There appears to be some indication that the stream formation process lasted for at least ,1000 yr. We also estimate the rotational bursting conditions for the three Geminid meteoroids and find tensile strengths of some 3 × 105 Pa. We interpret our results as being supportive of the argument that the parent body to the Geminid stream, (3200) Phaethon, is an aged cometary nucleus. [source]


High speed laser processing for monolithical series connection of silicon thin-film modules

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 3 2008
Stefan Haas
Abstract A detailed analysis of the monolithical series connection of silicon thin-film modules with metal back contact fabricated by high-speed laser ablation will be presented. In this study, optically pumped solid-state lasers with wavelengths of 1064,nm and 532,nm were used for the patterning process. The influence of various laser parameters on the performance of amorphous and microcrystalline silicon modules will be discussed. In particular, the line-scribing parameters for a TCO and Ag back contact system was analyzed in detail, since it is the most critical patterning step. A detailed description of the back contact ablation process will be presented and a criterion for flakeless patterning was defined. Finally the influence of the back contact patterning on the electrical behavior of silicon single junction cells was studied. The dark current density versus back-contact patterning line length was analyzed by means of a developed SPICE (simulation program with integrated circuit emphasis) simulation model. Copyright © 2007 John Wiley & Sons, Ltd. [source]