The use of lasers for welding has exhibited tremendous growth over the last decade for improving efficiency and
reducing costs in a broad range of industries. Much of these successes are based on the development and availability of
enabling technologies, which include improvements in process understanding, enhancements in laser sources and
systems, and continued development and progression in process technology for laser beam welding of macro and micro
components. The development of accurate numerical simulation techniques has provided an unprecedented opportunity
to view the transient nature of laser processing. Advancements in laser source technology include the introduction of
higher-power Nd:YAG lasers, utilizing diode pumped rods or disks, and fiber lasers, both providing the capability for
fiber optic beam delivery. Although CO2 laser systems continue to dominate thick section welding, this influence will be
challenged by emerging source technologies, namely high power fiber lasers. One of the most promising advances in
laser process technology is laser-arc hybrid welding, which is seeing considerable interest worldwide and is currently
being evaluated for various applications within heavy industry and manufacturing. The benefit of hybrid welding is the
synergistic effect of improved processing rates and joint accommodation over either of the processes viewed separately.
Other processing methods are also being developed to increase the utility of laser beam welding for industry, such as the
use of dual beams and beam manipulation. The continued advancement in process knowledge is seen as a key element
for facilitating the development of new processes and encouraging the acceptance of new source technology.