OBSERVATION OF A MAGNETIC-FIELD-INDUCED RESONANCE IN THE HOMOGENEOUS DEPHASING TIME FOR THE D-1(2)-H-3(4) TRANSITION IN PR3+YALO3

Using two-pulse photon echo excitation a strong resonance in the measu red homogeneous dephasing time as a function of magnetic field is obse rved in the H-3(4)-D-1(2) transition of Pr3+:YAlO3. The resonance coul d only be observed at low excitation energies since it otherwise was m asked by excitation intensity dependent extra dephasing processes in t he crystal. Thus intensity dependent dephasing processes may not only affect the apparent dephasing time of a system but may also mask other more subtle interactions in the materials studied. It is reasonable t o assume that the type of resonance observed could be caused by Zeeman induced level crossings in the active ion or in the host crystal ions or, possibly, that it could be due to coincidences between Zeeman lev el transition frequencies. However, based on current data of the Pr:YA lO3 system the observed resonance could not be unambiguously tied to s uch effects.