The optical spectroscopy of Cr3+ ions doped into near-stoichiometric LiNbO3 crystals, pure and co-doped with MgO, has been investigated. In the near-stoichiometric LiNbO3:Cr(0.2 mol%):Mg(2 mol%) crystal, the optical spectra resemble those previously observed for congruent LiNbO3:Cr:MgO samples when the total MgO content exceeds the 4.6 mol% threshold. The coexistence of two types of Cr3+ centre ([Cr]Li and [Cr]Nb) characterized the optical and luminescence spectra of this sample. The concentration equilibrium between the two types of centre is strongly displaced towards the [Cr3+]Nb centre, permitting us to obtain with accuracy the parameters of the broad bands. The R-line associated with the [Cr]Nb centre is only observable in the low-temperature emission spectrum. The Fano antiresonance lines present have been observed to be more pronounced for the near-stoichiometric samples than for congruent ones.
- impurity absorption spectra
- impurity states
- lithium compounds
Han, T. P. J., Jaque, F., Bermudez, V., & Dieguez, E. (2003). The role of the Mg2+ ions in Cr3+ spectroscopy for near-stoichiometric LiNbO3 crystals. Journal of Physics: Condensed Matter , 15(2), 281-290. https://doi.org/10.1088/0953-8984/15/2/328