Slowing atoms with a permanent magnet Zeeman slower & investigating fibre phase noise on an optical clock system.

Barron, Richard (2022). Slowing atoms with a permanent magnet Zeeman slower & investigating fibre phase noise on an optical clock system. University of Birmingham. Ph.D.

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Abstract

Optical atomic clock systems have recently broken out from being purely lab based devices to becoming portable and transportable systems. In order to facilitate optical atomic clock systems being used in non-lab based applications these systems must be made as robust, simple, and as affordably as possible. To that end investigations into non-powered versions of usually power hungry systems and off the shelf components for traditionally expensive ones are an attractive area of research. In this thesis investigations are made into a permanent magnet Zeeman slower to reduce power consumption, the effect of slits in Magneto Optical Trap (MOT) coils to improve physical robustness, and a Red Pitaya system for cancelling phase noise in fibres. The Zeeman slower designed, built, and characterised in this thesis is an iteration of previous work completed at the University of Birmingham being adapted for use in a system with reduced physical space on the system architecture. This presented a challenge on how to provide the magnetic field required for the Zeeman slower to work, without detrimentally affecting other parts of the clock system. The iqClock Zeeman slower design miniaturises previous work, and reduces the field in the MOT region, successfully forming a MOT of around seven million atoms. An investigation into the eddy currents that form in MOT coils was undertaken, proving the benefit of cutting a slit into the coil former to prevent inducted magnetic fields forming. The slit coils were tested against non-conductive and slit coils to determine the impact
of the eddy currents. These coils were then tested to ensure they provided the 40 gauss/cm gradient necessary to form the MOT. They were then used to help form the MOT system that the Zeeman slower was tested on. Fibre phase stabilisation is a key part of clock networks, and allows the comparison signals from physically distance devices. As some of the subsystems for the iqClock testbed system are located in separate labs the issue of fibre phase stabilisation came into play the process of connecting finished clock systems was in progress. A system was designed
and built to cancel the fibre phase noise present in fibres joining remote systems utilising "off the shelf" components.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):