The laser micromachining activities at the DTI have been going on since 2002. Here, we provide a review of the development of our laser laboratory including our recent investment in a femtosecond laser facility. In-depth information about the capabilities of this facility compared to the other lasers will be given. Finally, several industrially relevant case stories will be presented.
Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semi-transparent materials such as plastic or glass. The wish for an integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal workpiece in such a way that micro cavities are formed from the backside of the workpiece. The micro cavities must not penetrate the metal front side, but an ultra-thin layer of metal is left. It is possible to shine light through this layer. By ordering micro cavities in a matrix, different symbols can be obtained by shining light from the backside of the workpiece. When there is no light from the backside, the front surface seems totally untouched. This was achieved by laser ablation with ultra-short pulses.