Optical selectivity calculations have been carried out for the <sup>91</sup>Zr isotope for two-color resonant three-photon photoionization schemes. The density-matrix equations of motion were solved numerically for collinear, counterpropagating, linearly polarized laser beams having Gaussian temporal profile. Calculations were carried out incorporating the effects of Doppler broadening, magnetic sublevel degeneracy, and laser bandwidths. The selectivities and ion yields were determined for various Rabi frequencies and ionization rates. Thereby, the optimal Rabi frequencies for the first and second excitation steps and ionizaton rate for the ionizaton step were determined. The ionization efficiency as a function of detuning of the excitation lasers was also investigated. Two of the photoionization schemes investigated yielded a selectivity of ∼10, with an ion yield of ∼23%.
© 2003 Optical Society of America
(020.2930) Atomic and molecular physics : Hyperfine structure
(020.3260) Atomic and molecular physics : Isotope shifts
(020.3690) Atomic and molecular physics : Line shapes and shifts
(300.6360) Spectroscopy : Spectroscopy, laser
(350.3250) Other areas of optics : Isotope separation
Pragada V. Kiran Kumar, Manda Sankari, and Manda V. Suryanarayana, "Calculation of 91Zr optical selectivities in two-color resonant three-photon ionization schemes," J. Opt. Soc. Am. B 20, 1807-1816 (2003)