How to Make Your Photons Work Smarter, Not Harder

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. There two laser markets where the kilowatt race has not changed the scenery very much. Both of these markets are focused on precision and versatility instead of increasing to higher powers.

The first of market is tube cutting. Productivity gains in tube cutting have focused on material handling speeds and optimized nesting rather than increased laser power. In fact, more power can damage the other side of the tube resulting in rejected parts. Tube cutting machines are instead rated on the diameter, length, and the linear weight of the profiles they can handle and not on how many kilowatts are available.

Figure 1, output fiber for smaller core Corona

The second laser market bucking the power trend are flexible format machines. Just like desktop PCs were replaced with more versatile and comfortable laptops, the market for half-sheet cutting machines keeps growing rapidly. Historically, 4 by 4 foot cutting systems were limited to sign makers cutting thin sheet only. Recently, this market is experiencing a renaissance because of how affordable they have become for fast prototyping or small businesses who don’t need all the overhead that a can have. To provide more capability for these high-mix low-volume shops, flexible format laser tool manufacturers are asking for a wider range of processing performance from the fiber laser source.

At nLIGHT, we have utilized the incredible power of our CoronaTM technology to provide a unique and powerful solution to both markets. As a reminder, our Corona technology offers the capability to shape the laser beam inside the fiber laser, rather than using expensive optical solutions or manipulating the beam once it has left the fiber laser. By adjusting the beam inside the laser, we make the beam changes at the source, eliminating trade offs that often accompany external solutions.

Figure 2: 3mm stainless steel nitrogen cutting speeds with various power levels. The Mach cuts with the same speed as a much higher power laser.

Our newest version of Corona combines an incredibly precise beam of 50 μm, designed to cut thin metals at blazing speeds, with larger donut-shaped beams at 175 μm and our very popular 330 μm donut providing uncanny edge quality on thicker materials. This new Corona fiber configuration is available from 3 to 5 kW, which is the sweet spot for both of these markets. Figure 1 illustrates the output of this fiber laser. From the 50-μm core to the 330-μm ring, this laser new laser provides the flexibility to shift from precision cutting of thin features to excellent edge quality of thicker plate.

Let’s first dive a little deeper into the advantages the 50-μm core provides. While the fiber laser market has become engrossed with the kW label on the box, important factor is power density. In most lasers, the preferred fiber size is 100 μm to enable cutting thick and thin materials with a compromise solution that works for all scenarios. With a 100- μm fiber, increasing the power on thin sheet materials gives you more speed.

Figure 3, 19mm mild steel oxygen edge quality using

Our Corona technology provides photons that not only work hard, but also work smarter. With our 5-kW laser from the 50-μm core, you can cut thin metal at the same speeds of traditional 100-μm systems with 8 kW. In figure 2, you can see a comparison of typical fiber laser cutting speeds with a traditional 100 um core. The green bar shows what happens when a 50-μm core design is used. An incredible jump in speed without having to apply more power.

The tunability provided by our Corona technology allows the beam diameter to be increased from 50 to 330 μm delivering impressive edge quality for thicker plate as show in figure 3. In addition to excellent edge quality, this larger beam enlarges the kerf making it quick and easy to remove parts from the sheet.

Combining this incredible flexibility gives both tube cutting and small-footprint markets the versatility to achieve blazing fast speeds on thinner sheets and excellent edge quality edge quality on a thicker plate. Medium power lasers have never had so much flexibility.