A twist of quantum phase of a polariton condensate imposed by two external lasers leads to creation of a long Josephson juncion. By increasing the particle density, we drive the system to an instability that results in the creation of stable Josephson vortices. This research has been published in Nature Photonics. The experiment was realized in the group of Daniele Sanvitto from CNR Nanotec in Lecce. For a popular summary see News & Views.