LLNL patents digital-mask laser melting: goodbye to point-by-point scanning
Lawrence Livermore National Laboratory has filed a patent application that replaces the sequential scanning of Laser Powder Bed Fusion with a parallel exposure system. The technology uses high-power laser diodes and a programmable digital mask to simultaneously melt entire areas of the metal powder bed.
The approach promises to drastically reduce the production time of each layer, eliminating the need to trace point-by-point trajectories.
From the moving beam to the projected image
Application US20260273840A1 describes an architecture that transforms the way laser energy reaches the metal powder, moving from a sequential process to a parallel one.
In traditional Laser Powder Bed Fusion, a laser beam follows predefined trajectories to melt the component's sections. The system repeats the operation after each layer deposition.
The LLNL patent instead proposes an optical subsystem with a digital mask that generates a two-dimensional exposure pattern. The mask is updated for each layer, while the control adjusts the power density according to requirements.
- A computer-controlled mask defines where to send the energy
- A high-power laser source simultaneously illuminates multiple areas of the powder bed
- The geometry is imprinted in the light distribution before it reaches the material
Multiple optical configurations
The document envisages various architectures for transferring the image from the optical system to the powder bed, with solutions for extended work areas.
Configurations are envisaged with a complete image transferred onto the bed through a relay optical telescope. Alternatively, distinct areas can be controlled separately.
The patent also describes lenses that simultaneously direct energy onto different sections. For larger surfaces, a stitching approach with side-by-side exposures is proposed.
Power selection takes into account the composition and absorptivity of the material, particle size, layer thickness, and base plate conditions.
Optical technologies for modulation
The system uses components such as liquid crystal modules and polarizing mirrors to control where the energy is directed.
A patented configuration combines liquid crystals with a polarizing mirror. The element directs or rejects the energy based on the polarization modified by the control.
In previous demonstrations of DiAM technology, LLNL had used an Optically Addressable Light Valve without fixed pixels to shape the high-power beam.
The comparison with technologies such as MSLA and DLP helps to understand the logic: a two-dimensional image determines the regions to be transformed simultaneously. In the case of metals, the light must provide enough energy to melt the powder.
A decade of DiAM research
The question fits into a line of research started more than ten years ago, with experimental demonstrations already documented in 2017.
LLNL already documented Diode-based Additive Manufacturing (DiAM) in 2017, with demonstrations of metal printing using shaped light. The technology was subsequently licensed.
The publication should be read in the context of a broader patent family. The approach aims to parallelize the exposure of the powder bed, an objective pursued by the laboratory for more than a decade.
The process retains a layer-by-layer build, radically changing the way energy is distributed across each layer.
Implications for additive manufacturing
The technology could significantly reduce production times in laser metal melting, while maintaining control over energy density.
The described architecture replaces part of the sequential scanning with an exposure distributed over an area. The stated goal is to reduce the time required to form each layer.
The source consists of arrays of laser diodes that deliver energy over an extended area. In previous DiAM configurations, LLNL had combined diode arrays with pulsed lasers into hybrid sources.
The materials cited in the documentation include metals such as tin and stainless steel, indicating a potential versatility of the technology.
article written with the help of artificial intelligence systems
Q&A
What does the LLNL patent change compared to traditional Laser Powder Bed Fusion?
The patent replaces sequential laser beam scanning with a parallel exposure system. Instead of tracing point-by-point trajectories, a programmable digital mask simultaneously fuses entire areas of the metal powder bed. This approach promises to drastically reduce production times for each layer.
How does the optical subsystem with digital mask described in the patent work?
The subsystem generates a two-dimensional exposure pattern via a computer-controlled mask that defines where to send energy. A high-power laser source simultaneously illuminates multiple zones of the powder bed. The geometry is imprinted in the light distribution before it reaches the material, and the mask is updated for each layer.
What optical configurations are envisioned in the patent for transferring the image to the powder bed?
The document contemplates a complete image transferred onto the bed through a relay optical telescope, or distinct areas controlled separately. Lenses that simultaneously direct energy onto different sections are also described. For larger surfaces, a stitching approach with side-by-side exposures is proposed.
What optical components are used to modulate laser energy in the patented system?
A patented configuration combines liquid crystals with a polarizing mirror, which directs or rejects energy based on the polarization modified by the control. In previous demonstrations of DiAM technology, LLNL had used an Optically Addressable Light Valve without fixed pixels to shape the beam.
What does the selection of laser power depend on in the LLNL system?
Power selection takes into account material composition and absorptivity, particle size, layer thickness, and base plate conditions. The control adjusts power density based on these requirements. This ensures adequate exposure for each layer and material used.
