Spectral properties of LiTaO3:Pr3+ under high hydrostatic pressure

The high-pressure photoluminescence of the LiTaO3:Pr3+ system obtained for the pressure range from ambient to 232 kbar at 20 K and ambient temperatures is presented. The observed pressure red shift of all spectral lines representing the f-f transitions is related to the changes in F-2 Racach integral and the spin-orbit coupling with pressure. To analyse the deexcitation kinetics and the dependence of the intensity of the P-3(0) -> H-3(4) and D-1(2) -> H-3(4) on the excitation wavelength and pressure we propose a model of a Pr3+ trapped exciton with a hole localized at the Pr3+ and an electron at the Rydberg states bounded by the long-range Coulomb potential of the hole.