Diffusion process applied in fabrication of ion-exchanged optical waveguides in novel Er3+ and Er3+/Yb3+-doped silicate glasses

Planar optical waveguides fabricated in erbium doped glasses are promising photonics components operating at 1.5 μm, above all as optical amplifiers or waveguide lasers. In this study we focused on the influence of chemical compositions of Er³⁺ and Er³⁺/Yb³⁺-doped silicate glasses on the properties important for the sought applications, i.e., waveguiding and spectroscopic properties of the fabricated waveguides. Optical waveguides were fabricated by routine K⁺ ↔ Na⁺ ion exchange in a set of the glasses that had various contents of the RE ions. Waveguiding properties were studied by means of Dark Mode Spectroscopy at 671 nm while the chemical composition of the waveguides was determined using Scanning Electron Microscopy (SEM-EDAX). Surface concentrations of the lasing RE ions were determined by Rutherford Backscattering Spectroscopy (RBS) and related to the resultant photoluminescence properties. On the bases of the obtained experimental results the relations between composition of the substrates, especially content of the active ions, and experimental procedures will be presented with regards to real fabrication processes. Diffusion processes will be characterized by diffusion coefficients.