Acoustic substrate expansion in modelling dry laser cleaning of low absorbing substrates

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

“…Figure 2 shows a bark painting of an eel mounted on a background plate which in turn is mounted on a computer controlled translation stage for laser treatment and which allows precise positioning for low magnification imaging (off-line). High resolution imaging is completed with the in-line optical microscopy unit in the foreground of fig.2, which has been described in [8][9][10][11]. …”

“…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.…”

“…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.…”

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

“…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.…”

Imperfections in micro-optics characterised using focussed ion beam sectioning and imaging

“…Large numbers of monodisperse silica microspheres, with sub-micron to few micron diameters, are needed to fabricate synthetic opals for application as photonic crystals [1,2]. We have used such silica microspheres as one of the test particles in laser cleaning studies to test fundamental physical models of the short-pulsed-laser/particle/surface interactions that result in de-adhesion of a particle from the surface [7][8][9]. It is these latter studies that suggest that the optical properties of the silica microspheres are different than that of bulk silica.…”