Characterization of the densification induced by electron-beam irradiation of ge-doped silica for the fabrication of integrated optical circuits

Electron-beam irradiation of germanium-doped silica allows the fabrication of integrated optical circuits and offers several advantages over traditional fabrication methods based on photolithography and reactive ion etching. The increment of refractive index after electron-beam irradiation is mainly due to compaction of the irradiated material. In this paper, we present results on the densification behaviour as a function of different parameters such as size of patterns written, Ge-concentration and dose, the understanding of which is needed for the design of integrated optical circuits with the required properties.