Precise spatial and temporal control stabilizes the melt pool, while laser-integrated process monitoring ensures quality

All-fiber beam shaping is revolutionizing laser-based manufacturing. This capability is a commercially accessible reality in cutting, welding, and additive manufacturing tools released by leading integrators worldwide. These advanced tools increase productivity and part quality and introduce entirely new production capabilities, driving the displacement of legacy lasers and non-laser technologies in existing applications and spurring the development of new markets.

The latest application studies demonstrate how ring-shaped (‘donut’) laser beams overcome major obstacles in the laser powder bed fusion of metals. This includes key improvements in productivity and cost, a significant reduction of soot and spatter, the stable processing of difficult-to-print and crack-prone materials, and the ability to improve and spatially tailor material properties.

AFX fiber lasers have been shown to provide significant gains in L-PBF productivity for numerous metals and alloys, fundamentally changing the economics of L-PBF manufactured parts. The key enabler is AFX’s family of beam shapes which is optimized for L-PBF, including true SM (14 m Gaussian), a compact ring (40 m diameter), and multiple shapes in between, all with excellent beam quality. The beam profile is rapidly tunable directly from the feeding fiber with no free-space optics or other components that degrade performance, stability, or reliability. AFX fiber lasers are available at powers up to 1.2 kW, and the technology is scalable to higher powers and other beam shapes.

Laser powder bed fusion (L-PBF) is the leading additive manufacturing technology for producing high-quality, precision parts from a wide range of metals. L-PBF productivity is limited, however, by constraints on build rate and material quality imposed by the near-Gaussian beam shape of single-mode lasers employed in L-PBF tools. We have developed a novel fiber laser (AFX™) that provides a tunable beam shape optimized for L-PBF. The AFX beam is rapidly tunable, directly from the feeding fiber (no free-space optics), from true single-mode (14 m) to a 40 m ring, with multiple shapes in between, allowing real-time control of the thermal profile in the workpiece. AFX has been shown to increase the build rate by nearly 8x while maintaining excellent material properties (>99.8% density) and a large process window, enabling a new generation of high-productivity L-PBF tools for series production. We describe AFX technology and application results from several groups.

The battery market is approaching the tipping point. When battery prices fall below the industry consensus of $100/kWh, electric vehicles (EVs) will match internal combustion engine vehicles (ICEs) on the purchase price. The passenger vehicle market is the most significant volume application for batteries and has been pushing advances in battery technology and manufacturing efficiency.

It is well documented that increases in pump module power enables higher power DPSS or CW fiber lasers, but it is important to recognize that increasing the efficiency by which the DPSS or CW fiber laser is pumped drives down both system complexity and cost. Additionally due to the narrow absorption band of the common laser mediums like Ytterbium and Neodymium, it is advantageous to maximize the spectral overlap between the emission of the pump module and the absorption band of the host medium; one way to accomplish this is by the use of Volume Bragg Gratings (VBGs) to both narrow and stabilize (meaning to minimize change with current and/or temperature) the emission of the diode pump module.

Industrial lasers used for materials processing have become essential tools in a wide array of applications, including cutting, welding, drilling, cladding, marking, hardening, and additive manufacturing. The speed, quality, and process window are determined in part by the laser beam properties such as beam size, shape, and divergence. nLIGHT® has developed a new multi-kilowatt fiber laser, Corona™, that provides rapid tunability of the beam characteristics directly from the laser output fiber using a novel, all-fiber mechanism.

In this paper, we show results of further brightness improvement and power-scaling enabled by both the rise in chip brightness/power and the increase in number of chips coupled into a given numerical aperture. We report a new chip technology using new extra Reduced-mode (x-REM) diode design providing a record ~363 W output from a 2×12 nLIGHT element® in 105 µm diameter fiber. There is also an increasing demand for low size, weight and power-consumption (SWaP) fiber-coupled diodes for compact High Energy Laser (HEL) systems for defense and industrial applications.

From Lasik eye surgery and DVD players to the mouse on everyone’s desk, lasers are a ubiquitous aspect of everyday life. They’ve risen to the point of being indispensable tools – for materials processing, manufacturing, sensing, defense and scientific applications. But their widespread success has not been by happenchance. It has been driven by a multitude of performance improvements over the past several years.

The sheet metal cutting market is dominated by fiber lasers because of their unmatched combination of productivity, precision, and cost-effectiveness. Fiber lasers in the 2 – 4 kW range have become the workhorses for many fabrication shops, offering faster and more precise cutting of thin metal than legacy cutting technologies, such as CO2 lasers and plasma torches. Many fiber laser systems are, however, designed for cutting a limited range of metal thicknesses. Specifically, a small, tightly focused laser beam provides the fastest cutting speeds for thin gauges, but for thicker plates this small beam has significant limitations in edge quality and maximum thickness. Alternatively, a larger beam can improve the edge quality for thick plate because of the wider kerf, but with a substantial speed penalty for cutting thin sheet.

Lasers have become indispensable tools for materials processing, manufacturing, sensing, defense, and scientific applications. This success has been driven by laser performance improvements in several areas, including average and peak powers, wavelength coverage, temporal versatility (pulse duration and frequency, sophisticated waveforms), efficiency, power stability, long-term reliability, maintenance requirements, and operating costs.

Industrial laser welding continues to experience rapid growth, driven by numerous performance and cost advantages over alternative welding technologies. As laser welding makes inroads into existing products and enables new capabilities and applications for metal manufacturers, end markets are undergoing unprecedented change. For example, electrification and improved fuel economy demands are driving automakers to innovate in their design, assembly, and welding methods.

In this paper, we show results of further brightness improvement and power-scaling enabled by both the rise in chip brightness/power and the increase in number of chips coupled into a given numerical aperture. We report a new chip technology using new extra Reduced-mode (x-REM) diode design providing a record ~363 W output from a 2×12 nLIGHT element® in 105 μm diameter fiber.

The proverb, “Good things come in small packages,” is an apt description for a line of fiber lasers nLIGHT Inc. introduced at EuroBlech and Fabtech 2018. The Vancouver, Washington-based company designed and built the machines to “deliver the highest power available in the smallest size,” says Michael Hepp, nLIGHT’s high power/Corona fiber laser product manager. The fiber lasers are available in 3kW to 10kW and they “set the stage for future power scaling in small form factors.”

In today’s world of metal cutting, most of the fiber laser marketplace is dominated by one conversation: power. We’ve all seen the number of kilowatts painted in big bold letters on the side of flat sheet laser cutting machines. Ten, twenty, now thirty kilowatts. The sky is the limit on where the arms race will end. It is true; the productivity gains provided by these powers are inescapable.

With all the technological advancements of the past couple of decades, it is easy to overlook just how reliable weather forecasting has become. I can remember my father laughing at the local weatherman's predictions on the five o'clock news because they were so often just flat wrong.