Theoretical Analysis And Characterization Of The Refractive Index Profiles Of Copper Ion-exchanged Glass Planar Waveguides

In the paper, it is mainly focused on the study of the planar glass waveguides fabricated by copper ion-exchange, especially on the study of the ion-exchange process. The simulation and reconstruction of the index profile were implemented by analyzing the diffusion process with the experiment data. In this paper, firstly, it was introduced the development of the ion-exchange technology and also the testing technologies of the waveguides, including the characteristics and parameters of the waveguides and how to get them by experiments. Then the modeling ways and the common model of the ion-changed process were introduced in detail. Finally we fabricated the planar waveguides by copper ion-exchanged technology on Soda-lime glass and BK7 glass, respectively, and got the concentration profiles under the experiments condition of the Cu+ and Cu2+ on the base of the math model, the index profiles were also calculated by both concentration profiles and IWKB method. We analyzed the formation and the characteristics of the waveguides by the simulated results.The research findings and innovations of this work are described in brief as follows.1. The index changes were caused by Cu+ and Cu2+ in the region near the surface, and the changes in the deep region were caused by Cu+, Cu2+ only contributed to the index changes in the region near the surface. The index profile calculated from the ion concentrations also appeared to be a quasi-gradient index profile, when the exchange process was carried out for 5 minutes.2. When the exchange process was carried out for more than 5 minutes, the samples measured by prism-coupling technique showed no modes the samples measured by prism-coupling technique showed no modes. It could be caused by the decrease of the surface index, which could also be shownthat the waveguides were buried. Both the out-diffusion of Cu+ and the stress release of Cu2+ caused by anneal contributed to the buried waveguides.3. We fabricated single mode BK7 waveguides under the following conditions: temperature: 545℃, CuSO4 and Na2SO4(mol ratio 54:46), time: 5mins.4. We got a model to determine the index profile of the copper ion-exchange waveguides (the process including three kinds of ions:Cu+,Cu2+ and Na+).