Abstract
In the last decade, the fast development of high power laser systems has stimulated a variety of industrial applications in which lasers act as well defined local energy sources. In this context, the Institute for Nonmetallic Materials of the Technical University Clausthal together with the Wacker Chemie GmbH, both in Germany, have developed techniques for the laser sintering of high purity SiO2 preforms under clean-room conditions: SiO2 preforms have been sintered with CO2 laser systems providing an output power of up to 12 kW (cw.). It could be shown that, regarding their efficiency, state of the art CO2 laser systems are an alternative to heat sources commonly used for sintering. Moreover, laser systems have the advantage that a contamination of the material to be sintered can virtually be excluded. With the laser as a local energy source large SiO2 preforms can be sintered to graded structures without changing their geometry.
