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CO2 and Nd:YAG high power lasers have become established as machining tools in industrial manufacturing over the last
few years. The most important advantages compared to conventional processing techniques lie in the absence of forces
introduced by the laser into the workpiece and in the simple arid highly accurate control in terms ofpositioning and timing
making the laser a universally applicable, wear-free and extremely flexible tool /1,2/. The laser can be utilised costeffectively
in numerous manufacturing processes but there are also further applications for the laser which produce
excellent results from a technical point of view, but are not justified in terms of cost. The extensive use of lasers,
particularly in small companies and workshops, is hindered by two main reasons: the complexity and size ofthe laser
source and plant and the high investment costs /3/.
A new generation of lasers, the high power diode lasers (HDL), combines high performance with a compact design,
making the laser a cheap and easy to use tool with many applications /3,4,5,6/. In the diode laser, the laser beam is
generated by a microelectronic diode which transforms electrical energy directly into laser energy. Diode lasers with low
power outputs have, for some time, been making their mark in our everyday lives: they are used in CD players, laser
printers and scanners at cash tills. Modern telecommunications would be impossible without these lasers which enable
information to be transmitted in the form oflight impulses through optical fibres. They can also be found in compact
precision measurement instrumentation - range fmders, interferometers and pollutant analysis devices /3,6/. In the field of
material processing, the first applications ofthe laser, such as for soldering, inscribing, surface hardening and plastic or
heat conduction welding, will exceed the limits ofthe relatively low performance output currently available. The diode
laser has a shorter wavelength than the CO2 and Nd:YAG lasers making it more favourable in terms ofthe absorption
behaviour ofthe laser beam - an advantage that will soon have a significant effect on the range of its applications.
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