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In this article, it is demonstrated the generation of high pulse energy, high beam quality and high brightness mode-locked picosecond pulses from a compact Nd:YVO4 master oscillator power amplifier system. This system mainly consisted of a SESAM mode-locked picosecond seed generator and four-stage multi-pass amplifiers. A pulse picker was adopted prior to power amplifiers to efficiently reduce the pulse repetition rate. The maximum average output power of 65.5 W was obtained with a repetition rate of 496.85 kHz and a pulse duration of 16.9 ps, corresponding to a maximum pulse energy of 131.83 µJ and a peak power of 7.8 MW. While simultaneously, the output beam quality factors along the x axis and the y axis were measured to be Mx2=1.36 and My2=1.32, respectively, therefore, a brightness as high as 3.22 × 109 W·cm−2·Sr was achieved. As far as we all know, this is the highest brightness for a picosecond pulsed Nd:YVO4 MOPA laser at 1064 nm.

Additively manufactured tungsten and its alloys have been widely used for plasma facing components (PFCs) in future nuclear fusion reactors. Under the fusion process, PFCs experience a high-temperature exposure, which will ultimately affect the microstructural features, keeping in mind the importance of microstructures. In this study, microhardness and electron backscatter diffraction (EBSD) techniques were used to study the specimens. Vickers hardness method was used to study tungsten under different parameters. EBSD technique was used to study the microstructure and Kikuchi pattern of samples under different orientations. We mainly focused on selective laser melting (SLM) parameters and the effects of these parameters on the results of different techniques used to study the behavior of samples.