Persistent spectral hole burning induced by ion motion in caf_2:Pr³⁺:D and srf₂:Pr³⁺:D crystals

We have observed persistent spectral hole burning in a family of centers in CaF2+ and SrF2+ crystals in which the Pr3+ ion has multiple D-ion near neighbors. The hole burning is caused by light-induced D motion that leads to persistent changes in the local crystal field of the Pr3+ ion. Depending on the center and the temperature, side-hole or antihole structure is observed that has its origin in the second-order hyperfine interaction. The variation in the hyperfine splittings between centers is consistent with the separation between the ground state and the first excited state. © 1992 Optical Society of America. © 1992 Optical Society of America.