[en] Recent experimental results on charge transfer into excited states in collisions between singly and doubly charged ions with He, Ne, Ar, H₂ and O₂ are presented, respectively. The energy range of the ion beams of He^q+, Ar^q+, Ne⁺ (q = 1,2) ions is (70-170) x q keV. The optical measurement was performed by an Optical Multichannel Analysis System (OMA). The wavelength range covered was 200-800 nm. Different processes of excitation have been observed in single and double charged ion collisions with neutrals. The dependence of emission cross sections on the potential energy defect is discussed. (author)