The influence of radiation trapping on spectra and measured lifetimes of4F9/2 -4I15/2,4I9/2 -4I15/2,4I11/2 -4I15/2 and4I13/2 -4I15/2 emission bands in GeGaS glasses doped with erbium

Abstract
Behind the effect of radiation trapping, also known as radiation diffusion, is a series the sequential emissions and absorptions of radiation by participating atoms or ions. This effect is widely observed in glasses doped with Er3+ ions where there is a significant spectral overlap of 4I15/2 -4I13/2 absorbing and emissive interband transitions. This effect is known to be responsible for remarkably different characteristics of photoluminescence in bulk and powdered materials such as photoluminescence (PL) decay rate and PL spectra. It is worth noting that all above mentioned results refer to 4I13/2 and 4I15/2 manifolds. In the present paper we discuss the observed experimental data and report a Monte-Carlo model that allows us to simulate the observed effects of radiation trapping in 4F9/2 -4I15/2, 4I9/2-4I15/2 and 4I11/2-4I15/2 emission/absorption bands.