Diffusion elements in glass: comparison and optimization of the diffusion response in different substrates

Diffusion elements are fabricated by locally manipulating the ion composition of a glass substrate. For our experiments we use the silver sodium ion exchange technology. The effort of our work concentrates on the generation of arbitrary index distributions. Therefore we characterized two different types of special glasses--one of them showing linear, the other nonlinear diffusion response. To be able to optimize masks for the generation of arbitrary phase profiles we simulated the diffusion process numerically.