Studying the effect of nanosecond pulsed magnetic fields on the behavior of photon echoes in Y(Lu)LiF:Er samples it has been found that the action of a pulsed field leads to non-reciprocity and an asymmetric amplification of the photon echo signal. The effect strongly depends on the orientation of the crystals in the external magnetic field and on the orientation of the pulsed magnetic field relative to the direction of the laser pulses.
Shegeda et al. (Wed,) studied this question.