Share Email Print

Proceedings Paper

Optodynamic characterization of a laser cleaning process
Author(s): Vladimir B. Bregar; Janez Ivan Mozina
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Laser cleaning is an optodynamic process in which the optically induced removal of a liquid or a solid from a substrate is accompanied by a detectable acoustic signal. In our experiments we used both excimer and Q-switched Nd:YAG lasers and we examined both dry and steam laser-cleaning techniques. For the samples we used various metal, glass and marble specimens that were contaminated with particles, rust or a layer of paint. An acoustic wave, produced by the abrupt heating and detachment of the contaminants, was observed with a probe-beam deflection technique. We determined two characteristic parameters: the amplitude and the time-of-flight of the acoustic signal. The decrease of the amplitude and the velocity of propagation, which approaches sonic speed, indicate that the dynamics during the laser-cleaning process progressively weaken. According to this assumption the cleaning process is over when both parameters reach a constant value. If the irradiation with the laser pulses continues, the amplitude begins to rise again and time-of-flight decreases; and this is accompanied by a perceivable surface damage. No amplitude decrease and propagation-time prolongation were observed when the intensity of the incoming laser pulses was above the damage threshold for the particular substrate.

Paper Details

Date Published: 22 October 2001
PDF: 11 pages
Proc. SPIE 4402, Laser Techniques and Systems in Art Conservation, (22 October 2001); doi: 10.1117/12.445648
Show Author Affiliations
Vladimir B. Bregar, Univ. of Ljubljana (Slovenia)
Janez Ivan Mozina, Univ. of Ljubljana (Slovenia)

Published in SPIE Proceedings Vol. 4402:
Laser Techniques and Systems in Art Conservation
Renzo Salimbeni, Editor(s)

© SPIE. Terms of Use
Back to Top