Electron-phonon resonances in the spectrum of a rare-earth impurity ion
Perlin Yu.E., Kaminskii A.A., Enakii V.N., Vylegzhanin D.N.
Splitting of the phonon-free lines was observed in the absorption and fluorescence spectra of the Yb3+ ion in the YA103 crystal. It is shown that this effect may be due to the electron-phonon resonance.