Adaptive Optics for Laser Machining

Krystian Wlodarczyk, Rainer Beck, Piotr Jaworski, Jon Parry, Robert Maier, Duncan Hand

Overview

Adaptive Optics (AO) are a technology originally developed for astronomy. Optical elements, able to dynamically change their properties, are used to correct aberrations caused by atmospheric changes. Since comparatively low-cost adaptive optics have become available, such techniques are increasingly applied in medicine and industry.The aim of this work is to investigate commercially-available adaptive optic devices applied to laser materials processing. Beam shaping is often used for such applications to improve the machining outcome however static optics are typically used. Simple shaping of a laser beam may enhance the interaction of light with the work-piece, such as a circular top-hat profile for drilling applications or a square top-hat profile for surface marking or milling applications.
 

Figure 1 : Nanosecond laser machining a work piece with a Gaussian beam (left) and a square top-hat beam (right)

More complex patterns may be marked directly by imaging a mask to mark a surface structure (see Figure 2). Dynamic beam shaping optics give further potential to improve unique non-ideal (and possibly variable) laser beam profiles, enable rapid changes between pre-defined shapes even during a machining process and quickly realise new complex patterns.

Figure 2 : Producing data matrices with a Spatial Light Modulator (SLM).