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FEATURE MATERIALS PROCESSING ➤


according to Hein. In the figures presented at the Lasys press conference at the end of April, the VDMA reported that for 2013 there was an increase in exports to Asian destinations such as Taiwan, Malaysia, and Korea from a 15 to a 17 per cent market share, which was driven by the electronics industry in the Pacific Rim. ‘We now have a lot of new competition in China and other Asian countries, which have the advantage that they are located in the centre of enormous growth,’ stated Hein. ‘We already see, and will see further, tremendous potential in China, Korea and Japan. We have to cope with this by strengthening our R&D efforts to stay one step ahead. We have to recruit new staff who have the language know-how, the technical abilities, and who are inclined to spend longer in these far markets and to raise the flag for German and European technology.’


CO2 still strong


Although metal cutting accounts for approximately three quarters of uses for laser systems, application areas for CO2


systems


still represent a signification proportion of the materials processing market. ‘The CO2


laser still


has a huge application field. For the wavelength in the range of a CCO2


, some of these lasers in


the 10µm range can be used for cutting glass. A 1µm CW fibre laser wouldn’t be able to cut glass that easily,’ said Kleine. ‘A CO2


laser can cut


paper and leather and so on, something a fibre laser could never do, because the wavelength does not enable that. I don’t think that the fibre laser is going to cannibalise other product areas – it is an addition to our product portfolio.’ However, fibre lasers are being developed further to be used in a wider variety of


BEAM ANALYSIS


As high-power, solid state systems such as fibre lasers are being used in more manufacturing processes, measuring the power and profile of laser beams becomes more challenging. ‘The higher and higher the beam powers go, the more difficult it is to put materials in the laser path for purposes of measuring them,’ said John McCauley, product specialist at Ophir Photonics. ‘Each one of these products that


measure the lasers usually has some sort of damage threshold that they can sustain before they start to show signs of wear or even catastrophically fail,’ he continued.


Ophir uses thermopile and calorimetric


technologies to measure laser output from multi- kilowatt laser systems. The way thermopile technology works is that a laser is fired into the thermopile sensor – which causes a temperature difference,


22 ELECTRO OPTICS l JUNE 2014


explained McCauley: ‘There would be a heating up of the thermal element inside of the power sensor, or the heating up of cooling water that is circulating around the element − any type of temperature difference that can be measured and recorded and be correlated directly to amount of power that is being outputted by the laser.’ To cope with laser power


over 500W, cool water is circulated around the sensor to remove the heat,


which becomes more difficult with multi-kW powers. ‘The challenges have been developing products that will handle the amount of heat that is applied − in the past year or so, we have developed a 30kW power sensor, and even a 100kW power sensor,’ McCauley said. ‘We’ve had to develop new thermal sensors in order to supply a more massive amount of water to the cooling channel of the thermopile sensor. So, as a


result, the systems become larger.’


Ophir has launched a non-contact beam profiler − BeamWatch − which eliminates the issue of increasing power output, McCauley said: ‘Coming up with a non-contact beam-profiler has really been revolutionary for the industry, because there is no intrusion of the beam. The beam is passing right through − there is no necessity to apply any cooling.’


Laser cladding is increasingly replacing conventional hardening processes in the field of industrial steel processing


applications. ‘There is some work being done with different wavelengths with fibre lasers,’ Kleine said. ‘For example, a 2µm fibre laser could have advantages for processing polymers. A 1µm laser is not that effective at cutting or welding plastic − but a 2µm laser could do plastic welding and cutting.’ The VDMA’s Hein added that there are more applications being


taken on by the newer laser technologies: ‘The diode lasers are improving in some special fields such as manufacturing of plastic materials, welding aluminium, and so on.’ It is not just with the solid-state systems


where the laser processing industry is witnessing major developments, but also with short and ultrashort pulse lasers, which could lead to


@electrooptics | www.electrooptics.com


Darren Boxer


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