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The diode specialist

Warren Clark meets the team at Dilas, a company that has made a virtue of sticking to what it knows - laser diodes

During an economic period when companies that have grown too quickly and too broadly are falling by the wayside, it’s refreshing to find a company that has stuck to its guns, and ploughed a successful furrow in one particular niche of photonics. Dilas describes itself as ‘the laser diode company’. It’s an accurate description, because laser diodes are all it does. Other photonics companies produce laser diodes, of course, but mostly as an offshoot of the main business of lasers.

Dilas Diodenlaser was started back in 1994 by Dr Marcel Marchiano, an Argentinian who moved to Germany in 1978. He had previously held management positions at Heimann, where the main products were luggage scanners for airports using infrared detectors.

The seed for Dilas was sown during Marchiano’s time at Heimann, when the president imported a technology from the US with a view to manufacturing laser diodes in Germany. However, it was during the recession of the early 90s that the division that looked after laser diodes was sold off by Heimann. Marchiano decided to stay in the Rhine-Main area and start his own company, initially as an incubator for laser diode technology, with just four people in one room.

In the early days of Dilas, Marchiano received a lot of support from Siemens, both in terms of materials and also, as he says, ‘some political help too’. Laser diode bars were still very much in their infancy, and the biggest challenge – then and now – was cooling of the bars as power levels got higher and higher.

‘The main problem for laser diode bars is to remove the heat,’ says Marchiano. ‘We consulted with the Lawrence Livermore Laboratory in the early 90s, and later with the Fraunhofer Institute in Aachen, to develop microcoolers made from copper. We very quickly moved from concept into production, within a matter of months, and established ourselves as a pioneer of microcooling technology based on copper.

‘This enabled us to achieve very high power, and that led to many orders. We soon built a clean room here in Mainz, equipped with machines of our own design.’

Jorg Neukum is sales and marketing director at Dilas, and also looks after the company’s newest business unit, Dilas Industrial Laser Systems. He was previously European sales manager for Coherent Semiconductor, so brought a lot of experience in the photonics market when he joined Dilas in 2004. Neukum underlines the efficiency benefits offered by laser diode technology. ‘From input electrical current to the workpiece, a fibre-coupled diode laser has an efficiency of around 25 per cent. Compare this to a CO2 laser, where efficiency is around half of that. A diode-pumped YAG laser is down in the single digits, while lamp-pumped YAG lasers – at that time in the mid-1990s – had an efficiency below one per cent.’

Dr Marcel Marchiano

Indeed, the efficiency became the technology’s most significant selling point. ‘The diode business is still a niche market,’ says Marchiano. ‘Many people have concerns about how diodes should be handled, and most production line managers need a lot of convincing before they change technology. So, we teach people that they can save a lot of money on electricity, how they can be greener, and how they can save space – all by employing laser diode technology.’

Laser diode technology is competing with other laser sources in just about every market sector, from materials processing, to printing and defence, where the diodes are used in range finders and target designators. ‘The vast majority of solid-state lasers deployed now are diode-pumped,’ says Neukum. ‘For some applications, those needing very high peak power pulse lasers, lamp-pumped will still be the first choice, but for everything else, it’s diode-pumped.’

Dilas continued to develop laser diode bar technology. For example, in 1996 it produced a 1,200W direct diode semiconductor laser for use in welding applications. Following a constant trend to push power, the first diode bar the company produced was 10W; now, the same bar can offer 400 to 500W. The improvements have come about as a result of better cooling, a higher quality of raw materials (i.e. semiconductors), and advances in mounting technology.

The applications that drive the need for higher power are largely in the research field, and in particular, laser-based fusion facilities. For applications such as these, space is at a premium, so there are obvious advantages if they can use one 500W bar in place of five 100W bars. Back in 2005, Dilas delivered a single stack design that could house 2,200 bars to one such fusion facility.

Jorg Neukum

‘It’s very different for industrial applications,’ says Marchiano. ‘Higher power diode bars mean that more power has to be delivered to the device, and many industrial applications do not have the power budget to serve this, or the space to accommodate the larger cables. An existing power supply may simply not be enough to take advantage of the higher power diode bars.’

At the lower power level, though, there is still growth in the industrial uptake of diode lasers, including applications such as spot welding, plastic welding and so on.

Dilas now employs more than 200 people in Mainz, Germany, approximately 20 in Tucson, Arizona, US, and a further 10 in Shanghai, China. The US operation, which was incorporated in 2005, includes manufacturing and R&D, largely to support the specific requirements of the US defence market, while China also has a small manufacturing facility in Nanjing for products for the local market. Indeed, Marchiano believes China represents a huge potential for growth when it comes to diode lasers.

Neukum is keen to stress the leading position that Dilas enjoys in the laser diode market. ‘Dilas has by far the largest market share and is of double the size of most of its competitors.’

Marchiano puts much of his success down to personnel. ‘You have to have the right people,’ he says. ‘This is key. You can have all the technology in the world, but if you do not have the people, you will fail.’ Neukum adds that diversity is at the heart of the company’s ongoing growth. ‘We cover everything, including the defence and medical sectors, to diode-pumped solid-state lasers for industry use such as rod, disk or fibre lasers, to diodes for the printing sector, and now we have introduced our industrial laser systems unit covering the materials processing markets.’

This year, Dilas celebrates 15 years, and continues to go from strength to strength. It has recently expanded its facilities in Mainz, including a new clean room.

Marchiano concludes: ‘We are a very focused company. Back at the time of the telecoms boom, a lot of our competitors jumped ship and headed there. We stuck to what we know, and we continue to do it very well. All of our development is funded from cashflow, and we have never sought external funds. I hope that will continue for the next 20 years! In spite of this downturn, we are still hiring. We are getting ready for the years ahead for when all the markets are back up to their previous level – and they will all come back.’