Abstract
The aim of this project is twofold. Firstly, to quantify the impact of using a digital micro-mirror device (DMD) for diffraction and interference, in comparison with the theory for mechanical apertures. This was done by displaying masks of single and double slits on the DMD and recording the patterns it produced, when illuminated by a light source. Theoretical profiles were created using MATLAB and compared with the profiles produced by the DMD. There was a direct agreement between the position of the minima of the profiles from the DMD and theory, leading to the conclusion that the DMD had a negligible effect on the interference properties in comparison with the theory.
The second aim of the project was to demonstrate the principle of Lyot-masking using a DMD. This was done by imaging an object (a PSF or USAF 1951 target) through a slit and masking out the diffractive artefacts from the slit, using the DMD. It was found that the DMD was able to increase the contrast of the imaged object through Lyot-masking, though only when the slit was the limiting aperture of the system. The optimum mask size was found to be the size of the imaged slit on the DMD.
This work is relevant to applications in particle accelerators for beam profile reconstruction using interferometry, phase-space mapping, and the removal of diffractive artefacts caused by extraction mirrors or indeed any optical system.
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Speaker's Bio
Alex is a Masters by Research (MRes) student under the supervision of Prof Carsten Welsch and Dr Joe Wolfenden, Cockcroft Institute, Daresbury Laboratory, and Dr Theodoros Papadopoulos, University of Chester.