Adaptive Laser Beam Shaping for Laser Marking using Spatial light Modulator and Modified Iterative Fourier Transform Algorithm

In this paper we present the application of a modified iterative Fourier transform algorithm in combination with a closed loop feedback control using a CCD camera in order to improve the diffraction efficiency and uniformity of two-dimensional intensity distributions generated using a spatial light modulator (SLM). The impact of these improvements is demonstrated for nanosecond laser marking of a two-dimensional data matrix on a thin metal film utilising the dynamic nature of the SLM.