Product Code: ICA10_M207

Application of Adaptive Optics to Laser Micromachining
Authors:
Jonathan Parry, Heriot-Watt University; Edingurgh Great Britain
Rainer Beck, Heriot-Watt University; Edinburgh Great Britain
Nick Weston, Renishaw plc; Edinburgh Great Britain
Jonathan Shephard, Heriot-Watt University; Edinburgh Great Britain
Duncan Hand, Heriot-Watt University; Edinburgh Great Britain
Presented at ICALEO 2010

For many laser machining applications it is common to use some form of beam shaping to modify the typically Gaussian intensity distribution of the laser to generate an intensity profile that is more appropriate for the task. For example refractive elements may be used to generate top hat intensity distributions which are better suited to drilling applications or more complex profiles may be generated to mark patterns on a surface either with diffractive elements or masks. Dynamic beam shaping elements offer an advantage in terms of changing between shapes rapidly to quickly mark a series of shapes across a surface or even to modify the beam shape during a machining operation.

Machining demonstrations are presented with two types of adaptive optics (AOs) using millisecond and nanosecond pulsed lasers. The first AO is a piezoelectic actuated deformable mirror capable of supporting high average powers and enabling rapid (~1 kHz) modification of the mode shape of a beam. The second is a liquid crystal spatial light modulator which, although slower in response (75 Hz), can generate complex arbitrary shapes. The dynamic nature of these elements is used to improve the quality of laser machining results.