Spectroscopy of rubidium atoms in a femtosecond pulsed optical dipole trap

The spectral properties of atoms localized in an optical dipole trap formed by femtosecond pulsed radiation are studied experimentally. It is shown that the shift of the absorption line of an atom due to the interaction of an atom with the field of localizing radiation coincides with the shift of the line of an atom localized in the field of cw laser radiation. Theoretical analysis shows that pulsed radiation with experimentally achievable average intensity and duration of a pulse makes it possible to implement an atom localization mode in which the line shift is absent.