Examination of two-step fabrication methods for single-mode fiber compatible ion-exchanged glass waveguides

A computer model was used to study important two-step ion-exchange processes for fabrication of single-mode optical waveguides with fiberlike mode field distributions. As a first process step, a field-assisted method was calculated to have a better controllability than a diffusion method. As a second process step, field-assisted burial was found to optimize the coupling loss to fiber to 0.05 dB, but losses lower than 0.2 dB were calculated also for less complex diffusion process steps. On the basis of modeling, a solid state fabrication process was proposed, and the near field distributions of fabricated waveguides were measured to confirm the model.