Luminescence and spectral hole burning of Sm2+ doped in Li2O–SrO–B2O3 glass-ceramics

The Sm3+-doped alkali strontium borate glass-ceramics were obtained by heating of the as-made glasses in air, where Sm3+ ions were reduced to Sm2+ ions. The XRD, optical absorption spectra and luminescence of Sm3+ and Sm2+ ions were investigated. The excitation spectra of the 7F0 → 5D0 transition were measured in the region of 7F0 → 5D1 transition, where spectral holes were burnt within two of the Stark split 5D1 bands. The Sm2+ ions doped glass ceramics exhibit the persistent spectral hole burning at room temperature. The hole depth, which are burned by the DCM dye laser, are about 40% of the total intensity, respectively. It is concluded that the dominant burning mechanism is a photoionization of electron trapping at a site other than Sm3+ ions because of the absence of an antihole around the burned hole.