Oscillations of the photon echo intensity in a pulsed magnetic field: Zeeman splitting in LiLuF4:Er3

A method of high-resolution time-resolved optical spectroscopy using oscillations of the photon echo intensity in the presence of a perturbation, which splits the optical frequencies of the transitions of two or more ion subgroups, has been proposed and demonstrated. This method has been applied to systems in which the Zee-man effect is manifested. The transition frequencies of ions are switched by a pulsed magnetic field. Oscillations of the photon echo intensity were observed in LiLuF 4 :Er 3+ and LiYF 4 :Er 3+ . The first minimum corresponding to the accumulated phase of the electric dipole moment π/2 is reached in the pulsed magnetic field with an amplitude of ∼2 G at a duration of 30 ns. The Zeeman splitting in this field is ∼10 MHz, which is much less than the laser spectral width (0.15 Å ∼ 9 GHz). The g factor of the 4 F 9/2 ( I ) excited state of the Er 3+ ion in the LiLuF 4 matrix has been determined in zero magnetic field. The comparison with the g -factor value found from the measurement of the absorption spectrum in a magnetic field of 8 kG has been performed.