[en] It is described a method for separation resp. enrichment of isotopes in a vaporous mixture of compounds or atoms of the isotopes by means of a coherent polarized electromagnetic radiation. The isotope mixture is penetrated by a radiation whose frequency and field intensity are adjusted in such a way that the dipole moment of the groups of molecules to be stimulated is oscillating at least with its final amplitude manily in opposition to, the equivalent group of the other isotope, however, manily in q equal phase with the stimulating field. (HK)