The Resonance Ionisation Laser Ion Source (RILIS) is currently the most used ionisation method at ISOLDE, CERN's thick target. The reference system of the laser system gives the opportunity for stabilization and imaging of the beam to facilitate the optimisation and maintenance of the laser beam position, to achieve maximum ionization efficiency for the duration of an experiment . The beams are directed into the ion source cavities of either of the two ISOLDE target assemblies through windows in the magnetic-dipole mass separators. Wedge quartz plates are positioned in the middle of the laser beam paths from the laser table. Fresnel reflections of the laser beams from the surfaces of the plates are directed back to laser laboratory towards a dedicate reference beam monitoring and stabilisation system . However, only beams from one separator at a time can be observed and a fast re-set up and alignment for the reference area is required to observe the beams going in each of the two separators. The goal of the project is the upgrade of the current reference area to accommodate beams from both separators to be stabilized and monitored at the same time so that the time limitations during on-line operations are decreased.