Nephelauxetic inhomogeneous broadening of optical transitions

A highly monochromatic laser has been used to probe the inhomogeneous broadening of the R-lines in Cr3+ :LiNbO3. Fluorescence line narrowing (FLN) and radiative lifetime studies reveal that in LiNbO3 the broadening is caused by disorder which results in a distribution in the values of the electron-electron Racah parameters. Such nephelauxetic broadening in Cr3+ :LiNbO3 is in contrast to the broadening in Cr3+-doped glasses and disordered oxides, where distributions in the crystal field terms are dominant.