Efficient non-photochemical spectral hole burning in single-crystal SrO : Co2+

Efficient non-photochemical spectral hole burning is observed in the zero p honon line at 740 nm of Co2+ doped in single-crystal SrO. The Co2+ ions sub stitute for Sr2+ ions and occupy [1 1 1] off-centre positions in SrO. Due t o strain and a distribution of internal electric fields in the host crystal the eight equivalent sites can have different energies and different trans ition frequencies. The hole burning is attributed to light-induced rearrang ements between these eight sites. Such a process can be described in terms of the two-level systems model normally used for photophysical hole burning of glasses. The efficiency of the hole burning process is determined to be approximate to 0.07. Also, the luminescence spectrum of the lowest excited state at 1300 nm is reported. (C) 1999 Elsevier Science B.V. All rights re served.