In this thesis we explored various characterisation techniques that can be used to analyse lenses, including the characterisation of a focus and the characterisation of spherical aberration. We...Show moreIn this thesis we explored various characterisation techniques that can be used to analyse lenses, including the characterisation of a focus and the characterisation of spherical aberration. We used these techniques to analyse two near perfect lenses. We also designed and analysed seven lenses that were printed using the Nanoscribe Photonic Professional GT 3d printer. From this analysis we found that 3d-printed lenses performed as decent lenses. The waist of the focus, produced by the lenses, was smaller than 1 $\mu$m for all lenses. This was within 3 times the diffraction limited waist and the intensity in the focus was up to 360 ($\pm$ 30) times higher than if the lens had not been there. The Strehl ratio of each of the 3d printed lenses has been estimated, which all lie between 0.007 and 0.023. We found that the printed lenses behaved in a predictable manner and even though the micro-lenses show defects under optical inspection, their behaviour is predictable. We attempted to find the limits in quality, quantity and size that can be achieved using the Nanoscribe PPGT and made a beginning in answering this question. We found that micro-lenses created with the Nanoscribe PPGT can be used by the Quantum Optics department to enhance the intensity by acting as solid immersion lenses.Show less