Experimental study of the formation of ultracold RbCs molecules by short-range photoassociation

We have experimentally studied the formation of ultracold RbCs molecules by photoassociation at short internuclear range followed by spontaneous emission. The observation of new excited levels with respect to our previous work [Gabbanini and Dulieu, Phys. Chem. Chem. Phys. 13, 18905 (2011)] on both sides of the Rb(5S1/2) + Cs(6P3/2) dissociation limit gives information on the state responsible for molecule formation. The molecules are mainly formed in deeply bound levels of the electronic triplet ground state. The observed photoassociation transitions present differences in terms of saturation.