The emergence of techniques for producing cold and ultracold molecules triggered a wide research on the area in the last years, both in theory and experiment. Several theoretical proposals rely on the production of molecular ensembles in a single quantum state, thus the search for molecules in their ro-vibrational ground state has become an important experimental challenge. In our laboratory, we produce cold molecules from cold atoms via photoassociation (PA) process. For this presentation, I will talk about the latest developments of our group in the search for vibrationally cooled molecules of Rb2 and KRb. We begin discussing the basic theoretical treatment of molecules and the transitions between vibra¬tional levels. Later, we shall discuss the experimental methods, including the atomic trapping and cooling, molecular production and vibrational cooling via optical pumping. A new setup that is being developed for the experiment will be presented. Finally, I will show our previous results concerning to the pro¬duction of molecules, as well as the perspectives for reaching the fundamental vibrational state with the new experimental setup.
