Intensity parameters of Tm 3+ and Er 3+ in borate, phosphate and germanate glasses

Abstract

Intensity parameters τ λ of the Judd-Ofelt expression were obtained from oscillator strengths of the electronic transitions of Tm 3+ and Er 3+ in the visible and infrared part of the spectra. The parameters are interpreted by means of static and dynamic crystal field expansion. The τ λ 's of Tm 3+, Er 3+ and Eu 3+ are expressed as a function of the h (covalency parameter) parameter of the glass. It is concluded that vibrational interaction plays a dominant role in the origin of the forced electric dipole transitions of Tm 3+ and Er 3+ in glasses.