Modelling laser cleaning of low-absorbing substrates: the effect of near-field focussing

Pleasants, Simon; Luk’yanchuk, Boris; Kane, D. M.

doi:10.1007/s00339-004-2858-9

Cited by 13 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…9 -15 One recent and effective application is surface decontamination and cleaning. [11][12][13]16 Laser ablation can be applied, for example, for decontamination and decommissioning (D&D) of nuclear facilities at U.S. Department of Energy (DOE) complexes across the United States. For D&D applications, previous results 17 showed that laser ablation with an ultraviolet (UV) wavelength (266-nm) pulsed laser was most effective in particle generation compared with that with lasers of other (1064-or 532-nm) wavelengths.…”

Section: Introductionmentioning

confidence: 99%

Particle Generation by Ultraviolet-Laser Ablation during Surface Decontamination

Lee

Cheng

2006

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

A novel photonic decontamination method was developed for removal of pollutants from material surfaces. Such a method relies on the ability of a high-energy laser beam to ablate materials from a contaminated surface layer, thus producing airborne particles. In this paper, the authors presented the results obtained using a scanning mobility particle sizer (SMPS) system and an aerosol particle sizer (APS). Particles generated by laser ablation from the surfaces of cement, chromium-embedded cement, and alumina were experimentally investigated. Broad particle distributions from nanometer to micrometer in size were measured. For stainless steel, virtually no particle Ͼ500 nm in aerodynamic size was detected. The generated particle number concentrations of all three of the materials were increased as the 266-nm laser fluence (millijoules per square centimeter) increased. Among the three materials tested, cement was found to be the most favorable for particle removal, alumina next, and stainless steel the least. Chromium (dropped in cement) showed almost no effects on particle production. For all of the materials tested except for stainless steel, bimodal size distributions were observed; a smaller mode peaked at ϳ50 -70 nm was detected by SMPS and a larger mode (peaked at ϳ0.70 -0.85 m) by APS. Based on transmission electron microscopy observations, the authors concluded that particles in the range of 50 -70 nm were aggregates of primary particles, and those of size larger than a few hundred nanometers were produced by different mechanisms, for example, massive object ejection from the material surfaces. INTRODUCTIONLaser ablation is defined as the removal of material by laser irradiation from a surface of the material. Removed materials may be in the form of particulate matter, solid and/or liquid, and vapors. The interaction of high-power lasers with solid materials causes material removal through processes such as laser vaporization, desorption, sputtering, ejection, etching, spallation, and plasma generation. [1][2][3][4][5][6][7][8] Besides continuous research on laser ablation mechanisms, an enormous amount of research on applications using laser ablation has been performed. 9 -15 One recent and effective application is surface decontamination and cleaning. [11][12][13]16 Laser ablation can be applied, for example, for decontamination and decommissioning (D&D) of nuclear facilities at U.S. Department of Energy (DOE) complexes across the United States. For D&D applications, previous results 17 showed that laser ablation with an ultraviolet (UV) wavelength (266-nm) pulsed laser was most effective in particle generation compared with that with lasers of other (1064-or 532-nm) wavelengths. In this paper, the authors report, in detail, the production and transformation of particles when the UV laser was used on selected surrogate surfaces: Portland cement (cement) with or without a toxic heavy metal, chromium (Cr), prepared under laboratory conditions, stainless steel 316, and pure alumina (Al 2 O 3 ). The f...

show abstract

Section: Introductionmentioning

confidence: 99%

Particle Generation by Ultraviolet-Laser Ablation during Surface Decontamination

Lee

Cheng

2006

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

show abstract

“…This will soon be augmented with a Nd:YAG laser system. The KrF laser system and in-line optical microscopy system used to record before and after images of micro-scale regions of interest has been described fully elsewhere [8][9][10][11][12][13][14][15][16][17][18]. The scale of most artifacts for processing in laser conservation is macroscopic, and the resolution of most interest is that of human vision.…”

Section: Methodsmentioning

confidence: 99%

“…All of our studies have measured the laser cleaning result affected by a single laser pulse. Excellent removal efficiencies of alumina particles (0.3µm -tens of microns) and silica/glass microspheres (0.3 µm ->100 µm) from various glass surfaces using (i) high beam quality UV-copper vapour lasers [3], (ii) a XeCl excimer laser [4][5][6] and (iii) a KrF excimer laser [7][8][9][10][11][12][13][14][15][16][17] have been obtained. Single-laser-pulse fluence of the order of a few hundred mJ/cm 2 is required for laser cleaning.…”

Section: Introductionmentioning

confidence: 99%

Pulsed laser cleaning: comparing science with art and cultural heritage applications

Kane

Fernandes

2008

High-Power Laser Ablation VII

View full text Add to dashboard Cite

Laser cleaning research at Macquarie University has concentrated on a "hard science" approach to research and development of processes for optics and microphotonics applications (removing contaminants from optical materials). In more recent times we have carried out pulsed laser cleaning and processing studies for conservation of articles from Indigenous Australian cultural heritage. This paper introduces our research on laser cleaning of optical materials using UV pulsed lasers, and related surface modification and laser processing outcomes. It then introduces and reports some results from the laser conservation studies along with discussion of how activity in these two contrasting areas have informed our approach to the laser conservation studies, and vice versa.

show abstract

“…Large numbers of mono‐disperse silica microspheres with sub‐micron to few micron diameters are used to fabricate synthetic opals which are in turn used as photonic crystals (Fortes et al , 2009; Gruzintsev et al , 2009). We have used such silica microspheres as test particles in laser cleaning studies to determine the fundamental physics of the short‐pulse length laser interactions that result in de‐adhesion of particles from the surface (Pleasants et al , 2004a, 2004b, 2006). It is these studies that have suggested that the optical properties of the silica microspheres differ from those of bulk silica.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of imperfections in silica and chalcogenide glass microspheres using focussed ion beam milling and imaging

Kane

Chater

McPhail

2012

Journal of Microscopy

Self Cite

View full text Add to dashboard Cite

Key words: Focussed ion beam sectioning, glass microspheres, glass homogeneity, secondary ion imaging, secondary electron imaging. SummaryMicrospheres made from optical glasses such as silica and chalcogenide are used as both passive and active optical elements in micro-optics systems and devices. The homogeneity of the microspheres is crucial to their optical quality and performance in such devices and so it is essential, in optimizing such systems, that techniques with nanometer scale resolution are developed to measure the internal structure and homogeneity of such spheres. In this work an analytical protocol based on focussed ion beam milling, combined with secondary ion and secondary electron imaging, has been developed to study the internal homogeneity of glass microspheres. The results have shown that silica microspheres with diameters of three to five microns, fabricated by a sol-gel method, have internal inhomogeneities and voids that will lead to non-uniform optical properties. The FIB milling and imaging technique developed has been found to be a very useful method of studying such inhomogeneities, which have been proposed, but never previously observed, in glass microspheres. The FIB based technique has also been used on larger chalcogenide glass (Ga 2 S 3 :La 2 S 3 ) microspheres (diameter of order 70 microns) but no inhomogeneities have been observed at the spatial resolution of a few microns so far achieved for these larger microspheres. This study suggests that the FIB based milling and imaging technique may have potential for quantitative use in the measurement of morphological variations in such systems as well as in the study of aging processes in micron-sized glass spheres.

show abstract

Modelling laser cleaning of low-absorbing substrates: the effect of near-field focussing

Cited by 13 publications

References 15 publications

Particle Generation by Ultraviolet-Laser Ablation during Surface Decontamination

Particle Generation by Ultraviolet-Laser Ablation during Surface Decontamination

Pulsed laser cleaning: comparing science with art and cultural heritage applications

Evaluation of imperfections in silica and chalcogenide glass microspheres using focussed ion beam milling and imaging

Contact Info

Product

Resources

About