Enhancement of the isotopic selectivity in infrared multifrequency multiphoton excitation of OsO4 molecules in a supersonic molecular jet

A comparison is made between the multiphoton excitation of OsO₄ molecules containing a natural mixture of Os isotopes and similar excitation of ¹⁸⁷OsO₄ in a gasdynamic molecular jet using an infrared multifrequency laser field. It is shown that the highest isotopic selectivity and the best parameters of the multiphoton excitation process are achieved by using threefrequency excitation.