Effect of divalent cations on properties of Er3+-doped silicate glasses

In order to design silicate glasses suitable as the host media for the Er 31 ions we studied a role of divalent cations (magnesium, calcium and/or zinc) on the properties of the glasses. In this study we focused on comparing the glasses from the point of view of their spectroscopic properties and feasibility to fabricate optical waveguides by ion exchange method as depended on optical basicity of the glasses. The calculated Judd-Ofelt parameters Omega(1) corresponded well with the character of the bonding between erbium ions and surrounding oxygen ligands, i.e., changes of electron density caused by different divalent cations. The permeability of the glass structure for the diffusing ions studied using K+ and Ag+ <----> Na+ ion exchange fabrication of optical waveguides showed that the covalent character of the glass makes its structure more opened for the penetrating particles. The results of the study revealed that addition of zinc had beneficial effect on the properties of glass for utilisation in optical amplifiers and waveguide lasers. (C) 2004 Elsevier B.V. All rights reserved.