ABSTRACT
The laser machining marketplace is immense, and for the last few years, it has been averaging a growth rate of over 8" per annum. Most types of laser machining are based upon thermally modifying the workpiece. There are several different ways in which a laser can modify the material to create a mark, including engraving, layer removal and oxide formation, and thermal degradation, carbonization, bleaching, and foaming. Laser micromaching is a group of processes that involves fine machining at the sub-millimetre scale, sometimes involving micron-level features. Lasers used for micromachining applications are almost always operated in pulsed mode, typically using pulses shorter than a microsecond. Since the thermal penetration depth is related to the square-root of the pulse duration, shorter pulses can produce finer features. When laser cutting metals, the laser beam is focused through a copper nozzle to allow a jet of high-pressure gas to be co-axially aligned with the beam, creating a "melt and blow" effect.
