Projected optical dipole potentials for ultracold atoms suffer from coherent speckle noise, significantly degrading the potential shaping quality. In this thesis, the generation of incoherent light and its use to suppress coherent artefacts in the light field is demonstrated. Passing a coherent laser beam through a rotating optical diffuser or modulating the angular beam incidence onto the diffuser using an acousto-optic deflector are both shown to produce quasi-monochromatic light fields with controllably reduced spatial coherence. An alternative approach involves conversion of temporal to spatial incoherence, where modal dispersion in a square-core multimode optical step-index fibre efficiently induces dephasing. This results in temporally fast decorrelating, spatially incoherent, flat-top light complying with the requirements of off-resonant dipole traps with high trap frequencies. To characterize the light source, a lateral shifting Michelson interferometer has been constructed in order to measure the spatiotemporal coherence function. Finally, femtosecond lasers have been identified as a suitable spectrally broad light source with low temporal intensity noise.
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Projected optical dipole potentials for ultracold atoms suffer from coherent speckle noise, significantly degrading the potential shaping quality. In this thesis, the generation of incoherent light and its use to suppress coherent artefacts in the light field is demonstrated. Passing a coherent laser beam through a rotating optical diffuser or modulating the angular beam incidence onto the diffuser using an acousto-optic deflector are both shown to produce quasi-monochromatic light fields with c...
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