Using a camera feedback loop for phase retrieval in an iterative Fourier transform algorithm to calculate beam splitter phase gratings for parallel laser microstructuring

We are going to present an iterative Fourier transformation algorithm (IFTA) based computation-method for Phase retrieval of beam splitter elements. The power distribution between the separate beamlets will be controlled via a camera feedback loop in order to create an output distribution which is more closely fitted to the desired distribution than by solely virtual computation. It is taken into account, that by doing so the computation time will rise. Furthermore, we will show some parallel micro structuring examples with femtosecond laser beams utilizing this algorithm. All experiments will be conducted with imaging close to the resolution limit.