1. Focusing of high power single mode laser beams;Abt,2007
2. Beam Quality for Material Processing Chances and Challenges;Vollertsen,2010
3. The Characterization of Focusing Systems for High-Power Lasers with High Beam Quality;Maerten,2009
4. ISO 11146-2:2005, “Lasers and laser-related equipment – Test methods for laser beam widths, divergence angles and beam propagation ratios – Part 2: General astigmatic beams.
5. http://www.highyag.com/DE/index.html