Vertical-cavity surface emitting laser-diodes arrays expanding the range of high-power laser systems and applications

Thermal treatment may be by far the most frequent process used in manufacturing, but only at a few places lasers could make an inroad. For thermal treatment, homogeneous illumination of large areas at a lower brightness, and accurate temporal as well as spatial control of the power is required. This is complicated for conventional high-power lasers, while vertical-cavity surface emitting laser-diode (VCSEL) arrays inherently have these capabilities. Because of their fast switching capability and low power dissipation, VCSELs have been widely used for datacom and sensing applications. By forming large-area arrays with hundreds of VCSELs per mm2, their use can be further expanded to high-power applications. In this way, power densities of several W/mm2 are achieved, making the VCEL arrays an ideal solution for many heating applications, ranging from melting and welding of plastics and laminates to curing, drying, and sintering of coatings. A turn-key system concept has been developed allowing fast and easy configuring systems to the specifications of the applications. The compact and robust system can be built directly into the manufacturing equipment, thus making expensive fibers and homogenizing optics superfluous. These systems are now finding their first inroads into industrial applications and have been designed-in into commercially available production machines.