High brightness 500W blue laser source for DED processes

Blue laser diodes, with their short emission wavelength, are revolutionizing laser material processing, particularly for metals such as copper and gold. Achieving power levels suitable for industrial applications requires the combination of multiple lower-power sources while preserving high beam quality. The paper presents the design a preliminary characterization of a high-brightness laser source for Direct Energy Deposition (DED) processes capable of delivering up to 500 W leveraging on a two-wavelength spectral multiplexing approach. In first experimental tests at up to 300 W a Beam Parameter Product (BPP) of 7.7 mm mrad was measured, resulting in a record brightness of approximately B =510 000 W/m2·sr, which is already well-suited to open new possibilities in the DED processes with high-reflective metals. Furthermore, the system showed the potential to scale up to B = 850 000 W/m2·sr when the sources at the two wavelengths will be operated at full power.