Neutrinos are unique cosmic messengers, their weak interactions and lack of electric charge means they can travel from cosmic distances, without absorption or deflection. IceCube is a neutrino observatory constructed at depths of 1450-2450 m below the surface at the South Pole. The main objective of IceCube is to detect astrophysical neutrinos to enable a better understanding of high-energy cosmic rays including their production mechanism and also their origins.

IceCube observes neutrinos through detecting the light emitted by the products of neu- trino interactions. Characterisation of the optical properties of the glacial ice is necessary for the physical parameters of the neutrinos, such as their energies and directions, to be determined from the pattern and timing of the light detected. Embedded LEDs within the deployed modules enable the generation of in-situ light with five different wavelengths. This light can be detected by the detector array and used to determine the optical properties of the instrumented ice.

The main focus of this thesis was to investigate and parameterise the wavelength de- pendence of the absorption and scattering coeffi cients of the ice. The values found for the parameters characterising this wavelength dependence were consistent with previous mea- surements although slightly different values were obtained. While the new parameters are considered to be more robust than past measurements due to improved knowledge of the light emitters, it is recommended that this study is revisited when the observed anisotropic light propagation has been further modelled.

In addition to the main study into the wavelength dependence of the optical properties of the ice, investigations were also undertaken to characterise properties of the optical modules such as their orientation.

Calibration tools developed and used in this thesis will be of use when the IceCube upgrade devices are deployed, allowing our knowledge and characterisation of the ice to be improved significantly.