Efficient laser processing of high reflective materials, such as copper and gold, requires shorter wavelengths than those currently used for high power industrial applications, with blue being the optimal choice. However, the limited power of currently available blue laser chips poses important challenges in scaling the power to the required hundreds of watts while preserving the highest possible beam quality. The paper presents a new proprietary patent-pending architecture that allows achieving world record blue laser brilliance using commercially available high power lasers in TO9 package. The developed architecture is based on single emitters for best flexibility and reliability, which are organized in rows staggered along the fast axis; each row can then be placed side by side to other rows in order to spatially multiplex also along the slow axis. The optimized design gave a final architecture based on 3 rows for a total of 36 emitters that could be coupled into a 105 µm / 0.22 NA. Exploiting also polarization multiplexing and using commercially available 3.5 W diodes it is possible to obtain 220 W of coupled power into a 105 µm / 0.22 NA fiber, for a record brilliance of 150 GW/(ster m2). Following an accurate design phase some prototypes have been fabricated and characterized. Detailed results are presented at the Conference.
Laser-based additive manufacturing (AM) from metal powders is emerging as the new industrial revolution, although current fabrication approaches still require long mechanical post-processing to improve the final surface quality and meet the design tolerances. To overcome this limitation, the next generation machines are expected to complement laser AM with laser ablation (LA) to implement surface finishing and micro texturing already during the device growth process. With this aim, a new beam combiner to allow the real-time interchange of additive and subtractive processes using the same scanner head has been designed. Extensive tests have been carried out using a 6 kW continuous-wave laser similar to that used for the metal powder fusion and a nanosecond 100W pulsed source similar to that used for laser ablation.