High quality, high speed engraving using high average power nanosecond pulsed fibre lasers

Engraving of metals such as steel, aluminium, brass and silver using nanosecond (ns) pulsed fibre lasers has been well established using relatively low power lasers, typically in the region of 20W average power. Examples of very high quality 3D engraving are available, for instance in the creation of dies for coin manufacture, where a very low surface roughness is required together with high dimensional accuracy. However, such high quality results can only be achieved with low average power lasers, and trials made with high power fibre lasers using similar but scaled process settings do not yield the same high quality compared to lower power results. This research project will examine why it is not currently possible to achieve such results, and how this can be overcome. The work will be undertaken using the current pulsed laser product range of SPI Lasers together with laser products in development.

The research work will include detailed experimental work in the following key areas:

* Examination of the range of physical effects and material removal mechanisms which occur when using ns pulsed fibre lasers with defined pulse shapes.

* The difference between low average power and high average power ablation, particularly when the increase in power is achieved through higher laser pulse frequencies.

* Engraving strategies using combinations of lasers pulses having defined temporal shapes, peak power and frequency.

* Consideration of the ideal laser/system conditions to achieve fast, high quality results.

The project is sponsored by SPI Lasers who develop and manufacture high average power lasers for a range of manufacturing applications.  The selected candidate will be based within the High Power Laser Applications Group at Heriot-Watt but will spend short periods working at the company's application laboratories in Southampton. 

Please send inquiry emails to Prof. Duncan P Hand at D.P.Hand@hw.ac.uk