Spectral and kinetic peculiarities of the radiation trapping effect in doped materials

•A new scheme of excitation and detection is developed to investigate the RT effect.•Spectral redistribution of signal intensity due to the RT effect is registered.•A simple and illustrative model is proposed to take into account the RT effect.•RT lengthens the infrared luminescence decay time in the sample almost twice.

The results of detailed study of the radiation trapping effect in doped materials are presented. A special excitation and detection scheme is developed that allows in fluorescent signals significantly distinguish the contributions from the regions of the crystal excited directly by the laser radiation and excited by radiation transfer of the excitation in the non-irradiated part of the sample. This technique was used to investigate the radiation trapping phenomenon in infrared spectral region around 1.6 μm for YAG:Er3+ crystal excited by continuous and pulsed laser radiations at 970 nm wavelength. Spectral redistributions in fluorescent bands of the crystal under study were registered due to presence of the radiation trapping effect. The strong dependence of the luminescence decay times on geometry of both excitation and registration is revealed for the material under study. Within the framework of existing models of radiation trapping effect in doped solids, an analysis of the obtained results is carried out.