Preface for HPD'13 special issue

This Special Issue comprises selected papers from the 6th International Conference on High Power Diode Lasers and Systems. The HPD conference was established in 2007 with the aim of building new bridges between the academic, industrial and applications communities working in the field of high-power diode lasers. The Conference provides a stimulating and productive environment, where both new and experienced researchers can network to exchange ideas and latest results. Academic and industrial participants are also able to discuss long-term scientific and technological goals. Over the lifetime of the HPD conference, there have been many advances in laser diode technology, including increased power and brightness of single laser emitters, spectral beam combining for power scaling, an increased range of wavelengths, and the introduction of automated technologies for manufacturing and packaging laser diode systems. These advances in science and technology have made it possible for laser diodes to target a growing number of applications, ranging from cutting/welding of sheet metal, to medicine, projection displays and ultra-high power diode-pumped lasers for fundamental materials research and fusion ignition. The HPD Conference has been embraced by both the academic and industrial communities and has become an important fixture for the international high-power diode laser community.