For supersonic gas jet based beam profile monitors such as that developed for the High Luminosity Large Hadron Collider (HL-LHC) upgrade, density profile is a key characteristic. Due to this, non-invasive diagnostics to study the jet's behaviour have been designed. A Nomarski interferometer was constructed to image jets 30 µm to 1 mm in diameter and study changes in their density. A microscope lens has been integrated into the original interferometer system to capture phase changes on a much smaller scale than previous experiments have achieved. This contribution presents the optimisation and results gained from this interferometer
