Fabrication and characterization of Er³⁺-doped tellurite glass waveguides by Ag⁺-Na⁺ ion-exchange method using a dry electromigration process

Planar waveguides were prepared on 12Na₂O·10NbO _2.5·25WO₃·53TeO₂·1Er ₂O₃ ([NbWEr]) substrate glass by Ag⁺-Na ⁺ ion-exchange using a dry electromigration process. The optical properties of the waveguides were characterized and compared with those of [NbWEr] glass waveguides prepared by Ag⁺-Na⁺ ion-exchange by thermal diffusion. After ion-exchange by both a dry electromigration process and thermal diffusion, the transmittance of the glasses slightly decreased from that of the [NbWEr] substrate glass but frosting was not observed on these ion-exchanged glasses. The depth of the waveguide fabricated at 300°C by a dry electromigration process was about 8 μm and deeper than that at 380°C by thermal diffusion. On the [NbWEr] glass ion-exchanged at 300°C by a dry electromigration process, the stains seen in the [NbWEr] glass ion-exchanged at 380°C by thermal diffusion were hardly observed. Therefore, the dry electromigration process is promising due to the reduction of the process temperature and fewer stains.