Influence of temperature on the optical properties of LiTaO3:Cr

Optical absorption, photoluminescence, and luminescence lifetimes of Cr3+ in LiTaO3 were studied. It was found that a relatively sharp absorption band assigned previously to the no-phonon A24–E2 transition shifted by 68 cm−1 when temperature decreased from 300 to 5 K. A sharp, four-component emission band recorded at low temperature was assigned on the basis of lifetime measurements to the no-phonon E2–A24 transitions of Cr3+ ions in Li+ and Ta5+ sites. Frequencies of these transitions are lower than that of the sharp absorption band at the same temperature implying that the latter band is not the no-phonon A24–E2 line but it may be associated with a phonon satellite of the T24 state. Strong thermal quenching of broad band luminescence of Cr3+ was observed.