THERMAL MANAGEMENT


Meise, and targets those developing new, smaller laser systems in the power domain of hundreds of watts. It is only through relatively recent developments, however, that the waterless technique has come about. ‘Over the course of the last two to


three years, new mini compressors have emerged in the market, allowing the size of cooling systems to be reduced for lasers,’ said Meise. ‘Not only have compressors shrunk in size, they now have variable speed control, meaning they don’t need to


in the domain of hundreds of watts, integration is really starting to become key


For small assemblies


be turned on and off constantly [as with previous compressors] and are much more efficient. Te development of these variable speed controlled compressors is what has enabled the development of a water-free solution.’ Next-generation speed controlled


compressors, in contrast to traditional on-and-off compressors, offer very low vibration and noise levels, allowing them to be positioned much closer to the laser and cool it with a high level of stability without risk of disrupting its operation. Te


compressors used by AMS can even be run on a supply as low as 24V, which opens up the possibility of using batteries to power a portable laser system – a current ambition for one of AMS Technologies’ customers.


Embedded cooling In order to maximise floor space efficiency, cooling systems are starting to be integrated entirely within laser systems themselves, an approach currently gaining interest within industry, according to Meise. ‘We see customer needs for


smaller, portable laser systems where integration into small real estate is important,’ he explained. ‘While multi-kilowatt lasers will continue to use larger cooling systems located in separate rooms, for small assemblies in the domain of hundreds of watts, integration is really starting to become key.’ Embedding a cooling system


within a laser, while reducing its physical footprint, also increases the complexity of its design, making it difficult to access when being serviced. Te issues of maintenance increase


even further when water is involved, according to Meise, as the water will need to be routinely changed because of the build-up of algae and bacteria. ‘If you ask anyone that uses a water


system to cool lasers they will say that one of the problems is that aſter a


Diamonds are for lasers


Element Six, a manufacturer of synthetic diamond, has developed a series of chemical vapour deposition (CVD) diamond heat spreaders that can be found at the core of high power CO2


solid-state lasers. Through exploiting the extreme thermal conductivity, wide transparency range and low absorption of diamond, these heat spreaders remove much of the thermal load from the lasers’ internal components – such as the resonator – to enable a stable and enduring high optical quality of the laser beam. ‘In most cases, diamond is


18 and


used exclusively due to the fact that other materials fail under similar conditions of use,’ commented Henk de Wit, general manager and business manager of optical at Element Six. ‘In these cases, diamond is a truly enabling engineering material giving access to previously unreachable levels of performance. This means no hot spot formation, so no beam distortion through thermal lensing, and low component temperature, resulting in extremely long [equipment] lifetimes.’ When applied correctly,


LASER SYSTEMS EUROPE ISSUE 36 • AUTUMN 2017


diamond solutions offer the lowest operational temperatures under the highest power conditions, according to de Wit, who expressed that by using diamond components, the highest power density levels in both optical and electrical systems can be reached. Element Six was selected by


the European Commission’s Seventh Framework Programme for Research and Technological Development back in 2014 to help develop a new ultrafast pulse disk laser using its CVD diamond. The work was carried out as part of the three year


Element Six’s Diafilm ETC700 diamond heat spreader


project ‘Ultrafast High-Average Power Ti:Sapphire Thin-Disk Oscillators and Amplifiers’, which ended in December 2016. Within the project Element Six further developed its CVD


diamond material to be mounted to the titanium sapphire disk as a heat spreader, improving its thermo-optical effects and allowing it to be pumped at higher powers.


A mini liquid cooling kit (mLC-Kit) for use in a modular cooling setup


while the water turns green,’ he said. ‘Embedding this in a small confined area can create [additional] difficulties as the equipment still needs to be drained, cleaned and serviced.’ Despite these challenges,


embedded cooling systems are already being used in the medical domain, Meise continued, with a number of AMS Technologies’ customers having embedded chillers into their equipment assemblies. ‘Tey want everything to be contained in a single housing,’ he said. Glen Dimplex Termal Solutions


believes that embedded cooling systems will play an important role in Industry 4.0, where connectivity and the use and transfer of data will be crucial. ‘Te integration of a cooling


system is done in both a physical way


and by the way of exchanging data inside and with the surrounding system,’ Neumann explained. ‘So users can utilise the data being produced by the laser and cooling systems as a whole.’ Additionally, embedded systems


have to be designed using clever construction solutions to enable ease of maintenance despite difficult access, Neumann remarked. Glen Dimplex’s latest built-in chiller solution has been equipped with a refrigerant circuit that can easily be replaced in five steps and without the need of a refrigeration specialist. Meise expects embedded systems


to become more common in the future. However, they are not set to replace standalone chillers anytime soon, as the conventional format still favours systems comprising multiple lasers and machine tools that all need cooling.


@lasersystemsmag | www.lasersystemseurope.com


AMS Technologies


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40