Influence of Ambient Light on the Radiation-Induced Attenuation of Germanosilicate Optical Fibers in the Visible and Near-Infrared Domains

We investigated the influence of the ambient light on the radiation-induced attenuation (RIA) of Ge-doped optical fibers measured at the telecommunication wavelengths when exposed to a 60Co source and in the visible and near-infrared (NIR) domains when exposed to X-rays. From our results, it is possible to observe that this class of optical fibers is sensitive to the ambient light. Indeed, in all cases, their RIA value changes depending on the illumination conditions. In particular, the <tex-math notation="LaTeX">γ </tex-math> -ray irradiations revealed jumps in the measured RIA when changing the lamp of the irradiation chamber, whereas the X-ray irradiations reported that the relative photobleaching effect caused by the ambient light increases with the wavelength, up to ~1300 nm. The spectral study revealed no direct correlation between the absorption bands of the known Ge-related point defects and the external photobleaching phenomenon.