Cathodo- and radioluminescence of Tm3+: YAG and Nd3+: YAG in an extended wavelength range

We have studied the cathodo- and radioluminescence of Nd:YAG and of Tm:YAG single crystals in an extended wavelength range up to ≈5μm in view of developing a new kind of detector for low-energy, low-rate energy deposition events. Whereas the light yield in the visible range is as large as ≈104photons/MeV, in good agreement with literature results, in the infrared range we have found a light yield ≈5×104photons/MeV, thereby proving that ionizing radiation is particularly efficient in populating the low lying levels of rare earth doped crystals.