We study the phenomena connected with high concentration of incoming ions emerging during field-assisted migration in otpical glass. We find that ion dynamics are very different at concentrations higher and lower than a certain parameter called the transition concentration. To explain anomalies at high ionic concentrations, we introduce a supplementary local electric field. This field opposes to the field E0 existing in the glass at all concentrations of incoming ions and is connected with a local space charge. We investigate its dependence on concentration and on E0. These effects are studied using a model with concentration-dependent diffusion coefficients and mobilities. We present a method to obtain the concentration dependence of the relevant quantities. Theoretical curves are compared with experimental results measured in usual silicate glasses, during Ag+-Na+ exchanges.
Planar devices made by ion-exchange provide efficient active or active/passive functions. Compact amplifiers with 24 dB single pass gain for a single 980 nm laser diode pumping are presented, as well as 1535 nm lasers with 27% slope efficiency.
We present the analysis of a semi-leaky waveguide with the help of 3 different methods. Since the resulting numerical values still show some differences, the validity of these methods is discussed. Both theoretical and experimental studies of a semi-leaky waveguide show a maximum of the losses for an index of the superstate slightly greater than the index of the waveguide. We finally apply these results to design and characterize a polarizer based on the deposition of an anisotropic layer on an otherwise lossless waveguide.