Localised doping of Li-silicate glasses by Er3+ ion exchange to fabricate thin optical layers

Here we present a new method of fabrication of erbium containing thin optical layers that could be interesting for photonics active structures. These layers were fabricated by a purely thermal ion-exchange process at temperatures above the transformation point of the used glasses to minimise internal strain that arose in the layers during the fabrication process. In order to accelerate migration of rather immobile Er3+ ions, we used substrates with a high content of easily exchangeable Li+ ions. The substrates were prepared either as specially designed Li-glasses or glasses with intentionally created Li-containing surface layers. A number of nuclear analytical methods (i.e., Rutherford backscattering spectroscopy-RBS, and neutron depth profiling-NDP), as well as scanning electron microscopy (SEM-EDAX) were used to confirm presence of erbium in the glass surface and to determine the chemical composition of the fabricated layers. Photoluminescence spectra of the fabricated samples were measured to examine desired emission at the wavelength of 1.5 μm.