Rare-earth doped tungsten tellurite glasses and waveguides: fabrication and characterization

Tungsten tellurite glasses doped with Er3+, Tm3+, Pr3+, and Ho3+ ions were prepared by melt quenching. The glass matrix was the same for all types of glasses and had a high sodium content in order to allow the fabrication of waveguides using an ion-exchange technique. The absorption spectra of the glasses were measured and the Judd-Ofelt parameters Omega(q), were obtained from the experimental oscillator strengths of the f --> f transitions. Er3+ doped glasses showed a very high quantum efficiency when comparing the calculated radiative decay time with the measured lifetime of the I-4(13/2) metastable level. Ag+ Na+ ion-exchanged planar waveguides were successfully obtained in all types of glasses and characterized by the prism coupling technique. It turned out that the diffusion constant values are very similar for glasses containing different rare-earth ions with the same concentration, while, at least for the Er3+ doped ones, the diffusion constant changes with the ions concentration