The data in this repository contains the characterisation of fibres presented in the publication 'Multi-core anti-resonant hollow core optical fibre'. This includes microscope images of the fibres and the raw data files for the transmission, cutback and coupling measurements presented. These were taken to quantify the optical performance of the fibres, specifically the loss and inter-core coupling of light. Also included is the Matlab code used to process the data into the figure for the paper.