Flexible microassembly setup for optical beam transformation systems for high power diode laser bars and stacks
Microoptical beam transformation systems for high power diode lasers (HPDL) have been realized to couple the elliptical shaped beams of the individual emitters into standard glass fibers, so that such systems are meanwhile promising tools for direct material processing as well as pump sources for miniaturized solid state lasers and fiber lasers. Since the assembly part causes a significant amount of the total costs for beam transformation systems re-liable microassembly setups are necessary for the commercialization of beam shaped HPDL. This presentation focuses on our recent developments of reliable microassembling processes to realize micro-optical beam transformation systems for high power diode laser bars and stacks for the efficient coupling of the beam into optical fibers at reasonable costs. The micro-optical key component of the assembled beam transformation systems is a high N.A. lens of short focal length for the fast-axis collimation (F AC). For extremely precise fiber coupling of HPM bars an array of blazed gratings for beam deflection of the single emitter radiation in the slow-axis (redirector) is necessary as the second optical key component. Since laser diode stacks with e.g. 20 single bars whereas 20 fast-axis collimations are necessary are applied in fiber coupled modules the established automated adjustment and assembly processes are of particular interest.