An overview on the rear side ablation process and its characteristic mechanisms is presented. Starting with a description of the commonly used front side ablation and definitions of the ablation efficiency, we give results from our investigations of the model system black paint on floatglass, processed with q-switched Nd:YAG laser, operating with pulse durations of 360 ns and 8 ns at a wavelength of 1064 nm. In addition we present results from various other samples and laser sources such as Excimer laser. The experiments confirm that the efficiency for the rear side ablation process is up to two magnitudes higher than that for front side ablation and that the process is more efficient for the shorter pulse duration. Some quality aspects are discussed, that have to be taken into account, when rear side ablating. We present a first general model to explain the surprisingly high difference in the ablation efficiency and the fact, that the rear side ablation efficiency increases with increasing layer thickness. We address the initial thermal ablation step being threshold-determining and the final photomechanical step being efficiency-determining. Finally, we give an outlook to next approaches.
In this lesson, we present an overview on requirements for mobile laser cleaning systems with respect to safety, parameter regimes and performance. The given statements result from investigations over the last four years in developing and testing mobile laser cleaning systems to optimize their technique and to increase the applications. Most of the described features were developed together with restorers in outdoor tests, what gave us a good understanding of the restorers' needs and expectations. Starting with the restorers aim when restoring sculptures or buildings, we describe an ideal system, a complete system and presently used systems. We describe some useful features for mobile cleaning systems and the main aspects of safety philosophy.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.