A novel method for extracting oscillator strength of select rare-earth ion optical transitions in nanostructured dielectric materials

A new technique to obtain the oscillator strength of select rare-earth optical transitions in nanostructured dielectric materials (nanophosphors) is presented. It is based on the experimentally observed nanophosphor lifetime dependence on the embedding medium. A constant oscillator strength and parity-allowed electric dipole transitions of the RE ion emission are assumed. The oscillator strength is obtained from the slope of the 1/τij1/τij vs. n(n2+2)2n(n2+2)2 plot, where τijτij is the radiative lifetime of transition between states ii and jj, and nn is the index of refraction of the embedding medium. The use of the technique is illustrated for the Y 2SiO5:Ce nanophosphor.