Lasers are now used in a number of industrial applications owing to their excellent beam properties and the high degree of control that can be achieved over these. Depending on the type of laser, achieving high degrees of spatial and temporal coherence is possible. Many high-power systems are now also available for applications such as industrial cutting.
Green lasers – lasers that emit in the green region of the visible spectrum – are commonplace as laser pointers, interferometers, medical applications, and pump lasers for solid-state systems, such as titanium-sapphire lasers that are commonly used for the generation of temporally short laser pulses [1]. The sensitivity of the human eye to green colors combined with the high power efficiency of green lasers makes it easy to create beams that can be seen easily. This is advantageous e.g. in machine vision or calibration applications where a human eye needs to see the beam, too.
More recently, green lasers have been widely employed in additive manufacturing. The advantage of green laser sources over near-infrared lasers is that the interaction of the light with the surface, which is often a reflective metal like copper, iridium, or gold, results in much less reflection with green lasers and, therefore, less reflective losses and spatter [2].