Electronic and optical properties of oxygen deficient centers in silica and germanosilicate glasses beyond the DFT

Abstract : Electronic and optical properties of point defects present in pure amorphous silica (a-SiO2) and germanosilicate (Ge-doped a-SiO2) systems are of great interest because of their macroscopic consequences on systems as optical fibers or microelectronic devices. Often in the optical fiber, the silica core is doped with germanium to increase its refractive index. The presence of these dopants affects the optical properties of glasses, especially in harsh environments. Ionizing radiation of pure and germanium-doped silica induces several point defects. Oxygen-deficient centers (SiODC and GeODC) play an important role in the degradation of the optical fiber under irradiation, acting as precursor sites for the generation of other defects or being created through a knock-on process.