Evidence of Optically Stimulated Luminescence in Lu3Al5O12:Ce

Lutetium aluminum garnet, commonly known as LuAG, is a versatile material
finding numerous optical applications, and whose scintillation properties
have been widely investigated. In this study, experimental evidences of
optically stimulated luminescence (OSL) phenomena occurring in LuAG:Ce
crystals are shown. After demonstrating the possibility to optically bleach an
electron trap responsible for a thermally stimulated luminescence (TSL) peak
at 280 C (heating rate 1.7 Cs1) using red light, a direct measurement of
the OSL decay curve and of the resulting characteristic Ce3þ 5d-4f emission
spectrum is carried out. The assessment of the bleaching spectrum of the
TSL peak at 280 C reveals that light with wavelength in the 600–650nm
interval is the most efficient in depleting the TSL peak, making He-Ne lasers
suitable sources of optical stimulation. The finding of OSL features in LuAG:
Ce paves the way to new application perspectives. In particular, the
achievement of a good balance between scintillation and energy storage
properties of LuAG.Ce can drive a constructive integration between X-rays
imaging approaches based on photo-stimulable phosphors and those exploiting
scintillating materials.