Seurat Technologies has developed an optically-addressed light valve used for high repetition rate dynamic laser beam shaping for primary use in Metal Additive Manufacturing [1]. This patented Area Printing® process—analogous to a programmable stamp—delivers high-power laser pulses to a bed of metal powder that locally sinters and bonds to form fully dense metal parts across a wide range of industrial applications.

Area Printing® enables physical and economic scaling for Additive Manufacturing, while maintaining high spatial resolution, capable of printing features beyond reach of conventional manufacturing; with greater efficiency and minimal spatter defects.

In this presentation, we address the optoelectronic properties of the optically-addressed photoconducting insulator (semiconductor) and liquid crystals that control the dynamic beam shaping, in addition to the limitations and challenges met with the use of industrial power laser intensities. Specifically, we focus on the contrast ratio achieved between dark and bright fields, the resulting spatial resolution of the beam delivered to the print bed, and the temporal response of the processed beam, as it relates to the semiconductor photoexcited carrier dynamics and mid-bandgap states mediated relaxation pathways, and the related electrical properties of the beam shaping device.

Parasitic absorption imposes further device-level constraints that we characterize temporally and spatially via multi-physics finite element analysis of the thermomechanical response when the device is exposed to kW or MW levels of laser power. Key focus is placed on semiconductor and thermal management challenging the performance capabilities in light valves used in high power Additive Manufacturing.

[1]  https://www.seurat.com/area-printing