The Bose-Einstein Condensate group at Laboratoire de Physique des Lasers studies superfluid dynamics of a degenerate bosonic gas confined at the surface of a bubble. We have evidenced in the bubble the formation of a vortex lattice when the gas is set into rotation, and observed the thermal melting of the lattice at large rotation frequency. In the internship, we propose to develop a new imaging system at a shorter wavelength to improve the imaging resolution, with the final goal of imaging the vortices directly inside the trapped gas.