This thesis presents computational and experimental techniques to generate light potentials of arbitrary shapes holographically using a phase-modulating liquid-crystal
spatial light modulator (SLM) for experiments with ultracold atoms. Many quantumsimulation and quantum-computing experiments using ultracold atoms have benefited
from programmable local control on a microscopic scale. Inhomogeneities in the light
potentials used in these experiments must be reduced to mitigate dephasing effects or
heating of the atoms. Further, in applications where laser power is limited, a high efficiency is desirable. Here, I demonstrate the generation of holographic light potentials
with a root-mean-squared (RMS) error below 1% and a measured efficiency of up to
∼ 40%. I show that in a Fourier imaging setup, for light potentials which occupy a
significant fraction of the addressable area in the image plane, a parasitic effect on the
SLM known as pixel crosstalk or fringing field effect limits the accuracy of the light
potential. By modelling this pixel crosstalk and by compensating for its effects, the
error in the light potential is reduced by a factor of ∼ 5. A gradient-based optimisation algorithm is employed to calculate the SLM phase pattern for the desired light
potential. To reduce experimental errors, we measure the wavefront of the incident
laser beam to within λ/120 and employ an iterative camera feedback algorithm. To
downscale the light potentials to a microscopic scale, a high-NA microscope objective
is used. Finally, a fast method to calibrate the experimental setup is demonstrated,
reducing the runtime from ∼ 3 hours to ∼ 5 minutes, maintaining an RMS error of
below 1% in the resulting light potentials.
| Date of Award | 24 Feb 2025 |
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| Original language | English |
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| Awarding Institution | - University Of Strathclyde
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| Sponsors | University of Strathclyde |
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| Supervisor | Stefan Kuhr (Supervisor) & Jonathan Pritchard (Supervisor) |
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