Temperature Dependence of Radiation Induced Attenuation of Aluminosilicate Optical Fiber

Abstract

We investigated <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> the temperature influence on X-ray radiation-induced attenuation (RIA) levels and kinetics of an Al-doped single-mode optical fiber (OF) in the visible (vis) and near-infrared (NIR) spectral domains (400 nm– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2~\mu \text{m}$ </tex-math></inline-formula> , from room temperature (RT) up to 300 °C). The RIA spectra in the visible show no significant variation up to 200 °C. Above this temperature, the induced losses begin to decrease. The NIR RIA, on the other hand, appears to be more temperature-dependent, showing a monotonic decrease with increasing temperature throughout the whole investigated range. By studying the RIA growth kinetics at 1550 nm at the various temperatures, a linear dependence was found between the RIA levels and doses at which a steady state is reached, suggesting a direct generation process of the induced defects. Finally, the combination of the measurements led to the attribution of the RIA in the NIR domain to a single absorption component, whose generation process is correlated with the defects absorbing in the visible and characterized by a continuum of absorption states.