Infrared femtosecond laser pulse-induced three-dimensional bright and long-lasting phosphorescence in a Ce^3+-doped Ca_2Al_2SiO_7 crystal

Abstract

We report on three-dimensional bright and long-lasting phosphorescence in a Ce³⁺-doped Ca₂Al₂SiO₇ crystal. After we scan with a focused 800-nm femtosecond pulsed laser, the path traversed by the focal point of the laser in the crystal emits bright and long-lasting phosphorescence that can be seen with the naked eye in the dark even 10 h after the removal of the activating laser. Absorption spectra of the crystal show that defect centers have formed after the laser irradiation, and the absorption that is due to the defect centers decays with time. It is suggested that a mechanism of the long-lasting phosphorescence consists of a thermostimulated recombination of holes and electrons at traps induced by the laser irradiation at room temperature.