Design of multi-aperture beam integrators for homogenization and local controllability of irradiance distributions from high power VCSEL systems

High power VCSEL systems are a versatile and powerful tool for thermal treatment in industrial production where they enable a very homogeneous and locally controllable irradiance distribution at small working distances. Due to the inherent divergence of VCSELs, both characteristics degrade with increasing working distance. Depending on the size of the used VCSEL system, already at distances of about 100 mm the irradiation is not homogenous anymore and the local controllability is strongly limited already at even smaller distances. To extend the application range of VCSEL systems for increased working distances while maintaining homogeneity and local controllability, two multi-aperture beam integrators have been designed. Simulation results as well as measurements of a prototype system are presented in this work.