Optomechanics explores the interaction between light and mechanical vibrations. As a typical example, one can consider a Fabry-Perot cavity (i.e., optical mode), in which one of the two mirrors is vibrating (i.e., mechanical mode). To display quantum properties, a mechanical mode must be cooled down close to its ground state (i.e., down to a few quanta of vibrational energy), which is typically achieved by leveraging the optical field. Sadly, when considering multiple degenerate modes, one cannot apply conventional cooling techniques that have been devised for single modes. Throughout this internship, the candidate will experimentally implement a new cooling technique intended to achieve the first-ever cooling of degenerate mechanical modes. Compared to former strategies, here, a spatial light modulator is used to spatially shape the wavefront of the light beam. Such a modulation enables to exert simultaneously adapted optical forces on each mode in order to reduce (i.e., cool) their individual vibrations. A funding is available to continue and expand this internship through a PhD.