Spatial distributions of NBOHCs in an electron and gamma-ray irradiated germanosilicate optical fiber
Abstract
The spatial distributions of emitting point defects are characterized by Confocal-Micro luminescence (CML) spectroscopy in the transverse cross-sections of a 4-steps Ge-doped multimode optical fiber irradiated with either -rays or electrons. The measured cartographies of the Non-Bridging Oxygen Hole Centers (NBOHCs), under an excitation at 633 nm, notably differ between the fiber samples irradiated with electrons (~100 MGy) and those exposed to γ-rays (9 MGy). Additional cathodoluminescence (CL) have been performed. The observed in-situ kinetic measurements of the NBOHC evolution as a function of the electron beam irradiation time agree with the CML result analysis. The influence of three main factors on the generation and bleaching of emitting defects are characterized: the irradiation type, the accumulated dose and the type of defect.