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The Laser User Magazine
Issue 051 - Summer 2008
Picosecond lasers and their industrial applications
Author: Gerry Jones
The use of laser technology is now well established in many industry sectors. In almost all cases its use has been based upon the laser being a thermal processing tool. It has proven itself to be a truly efficient, accurate and productive tool particularly when the laser interaction is precisely controlled. However, with the advent of ultra-short pulse lasers so-called 'cold processing' is possible i.e. material removal with negligible residual heating. Such processing is very attractive for certain applications, including expanding markets such as the manufacture of semi conductor and solar panel components.
For metals, semiconductors or dielectrics the electron to atom energy transfer time is in the order of 10 picoseconds. If the laser is to process the material with negligible mechanical and thermal modification then the laser pulse duration must be less than this. When this is achieved material is removed by sublimation.
Few commercial lasers provide such short pulses, those that do have generally been limited to very low average powers, typically less than 10 watts. These lasers produce good results but their low average power implies slow processing and in general productivity is deemed to be insufficient for widespread industrial acceptance. The advent of the Trumpf TruMicro 5050, a picosecond laser built for industrial use with high reliability and an average power in excess of 50 W provides the required throughput to be a cost effective tool.