Measurement of the fraction of reabsorbed light in an Er3+-doped glass

We report on an original continuous holographic grating technique to quantify the excitation transport within the excited states of erbium ions. We measure a very long range effect well beyond the μm distance which is attributed to radiation trapping. We demonstrate that 30% of the emitted light is reabsorbed inside the sample due to total internal reflections (TIR). The effect of reabsorption is totally removed when TIR are reduced by refractive index matching of the surroundings of the sample. PACS 78.20.-e