Evidence for existence of the trapped exciton states in Pr3+-doped LiNbO3 crystal

We present the arguments for existence of the Pr3+-trapped exciton system in the LiNbO3:Pr3+ crystal which is responsible for the non-radiative processes quenching the radiative emission from the 3P0 state. We report on the LiNbO3:Pr3+ absorption spectra, photoluminescence spectra for different excitation, the 1D2 → 3H4 luminescence excitation spectra and the excited state absorption (ESA) spectra. We estimate the semi-empirical parameters describing the LiNbO3:Pr3+ system (the Racah integrals, spin-orbit coupling and crystal field parameters) and parameters describing the configurational coordinate diagram of the Pr3+ trapped exciton.