TRUMPF embraces kilowatt disc laser technology

Europe is our largest market, although our North American and Asian businesses are also well developed. The company's sales are split approximately 25% for the German market, 20% North America, 20% for Asia, 25% Western Europe and 10% rest of world.

Which lasers does TRUMPF offer?
We produce solid-state and gas lasers. Our gas lasers are solely CO₂, ranging from 1 to 20 kW, and are used for cutting and welding. These are based on both fast-axial-flow and diffusion-cooled designs.

On the solid-state laser side, we make both lamp-pumped and diode-pumped systems. Our lamp-pumped pulsed lasers start at 20 W and go up to 500 W, and continuous-wave (CW) sources from 500 W to 4 kW.

Our diode-pumped rod lasers start at 1 kW and go up to 4.5 kW. We also make diode-pumped disc lasers starting at 250 W (CW), up to 4 kW.

TRUMPF's history

We are also launching a diode-pumped Q-switched laser. This has diffraction-limited output and emits extremely stable pulses in the nanosecond range. These lasers are intended for micromanufacturing applications such as drilling and engraving of fuel injectors for automobiles, and structuring cylinder surfaces or solar panels. We are offering this laser at 1064 nm; green at 532 nm and ultraviolet wavelengths are also under development.

We are one of the largest manufacturers of diode-pumped Q-switched solid-state lasers for marking applications worldwide.

What is your most important market?
This is a hard question to answer! You can segment CO₂ lasers into two markets: cutting and welding. Most lasers emitting less than 7 kW go into cutting applications, whereas all those above 7 kW go into heavy-duty welding applications such as steel manufacturing and ship building.

On the solid-state side, it's a lot more complicated. We have a diverse customer base at up to 1 kW. Applications range from the welding of the housing of pacemakers and miniature devices in electronics, to cutting very fine metal parts.

Almost all of the lasers above 1 kW are used for the macrowelding applications found in production lines in industry. Many of these go into the automotive industry. We have had great success selling our systems into production environments in the past five years, especially for the welding of car bodies.

Continuous-process welding applications, such as tube manufacture, are another important market for us. The vast majority of stainless-steel tubes today are welded with a laser, many with a TRUMPF laser.

I am convinced that micromanufacturing will be an important market in the future. The laser has unique strengths and can create structures that cannot be made in any other way. I am absolutely certain that the trend to make things smaller will coincide very well with the abilities of the laser as a tool.

Have you seen a shift from gas lasers to solid-state lasers?
No, not really. The CO₂ laser is ideal for cutting and also has a very attractive price point. Compared to many solid-state lasers available today, the CO₂ laser still has very favourable beam characteristics. The physics of the cutting process favours the CO₂ laser, in relation to the energy absorbed by the metal.

The CO₂ laser is also eye-safe, which is tremendously important. The cost connected with making a solid-state laser eye-safe is not to be underestimated. TRUMPF has tried to introduce solid-state laser-cutting machines because we have both technologies in-house, but the success has been limited. In our mind, the CO₂ laser has a long life ahead of it with regard to cutting.

Welding demands high flexibility when it comes to manipulating the laser beam - you need to use a robot. Here, the solid-state laser has unique advantages in terms of beam delivery. There are also certain welding applications where the YAG laser is plainly better. For example, if you want to weld on the surface as opposed to a deep weld, this cannot be done with the CO₂ laser because of its absorption characteristics. The YAG laser also has advantages in pulsed applications such as fine welding and fine manufacturing.

Are you developing fibre and disc lasers?
We have a range of disc lasers and consider ourselves the technology leader in this field. TRUMPF is convinced that the disc laser is the best concept for multi-kilowatt laser systems when you consider the cost per watt.

Having said that, we think the fibre laser is a tremendously interesting concept. We are looking at the fibre laser, but we think the concept is still at an early stage of development.

We think that the disc laser is where the turbocharged direct-injection diesel engine is in the car industry today, and the fibre laser is where the hydrogen engine is. In other words, the fibre laser is a promising concept that might have important applications in the future. We are not exactly sure, as yet, what niche the fibre laser will fit into. It is still too early to say if this is an industry-worthy product.

We are not interested in setting world records in terms of power. We are interested in setting the world record in industry-worthiness. That has been our success in the past and we will follow this track in the future. We will only introduce technology and offer it to our customers when we are absolutely certain it is industry worthy. Today, we can say that this is the case for the disc laser, but not the fibre laser.

What applications will the disc laser find and what technology will it displace?
We think that the disc laser will replace the conventional lamp-pumped solid-state laser to a large degree. It offers everything that the lamp-pumped laser offers and it has the beam quality necessary for remote welding. The beam on-times will be 90% for the disc laser, in typical industrial applications, versus 50% for the lamp-pumped source.

The time between exchanges of the pump source is also an issue. In the case of the lamp-pumped laser, we have to exchange the lamps between, say, 1000-2000 h. The disc laser's diodes have to be replaced after 10,000 h at the soonest, but we expect the diodes to last at least 20,000 h. The wall-plug efficiency will go up to 20%, compared with 3-4% for the lamp-pumped laser.

There are still many applications where the lamp-pumped system is preferable. But if you look at car-body welding, you see the disc laser replacing the lamp-pumped system. The disc laser is the laser of choice in this application.

Europe - and especially Germany - is still, to my mind, the most important laser market in the world, and I am certain it will remain strong. The level of sophistication of our customers in Europe and Germany is very high and the cost pressure on these customers is also high. They need to look for ways to differentiate themselves, which they can do through advanced manufacturing methods.

Therefore, I think the laser market will remain strong in Europe. I do not expect the German and Western European markets to grow at high rates - those markets are already large and other markets are growing faster.