[16p-213-1~14] 16.1 Fundamental properties, evaluation, process and devices in disordered materials

▲ [16p-213-9] Photo induced absorption on Mg doped silica glasses

〇Edson Haruhico Sekiya¹, Masafumi Iwata¹, Tomoya Okazaki¹, Kazuya Saito¹ (1.Toyota Tech. Inst.)

Keywords:silica glass, Optical defects, Magnesium

Actually Yb doped fiber lasers (YDFL) operating in continuous wave and single mode with output power in kW order are commercially available and used in many applications. Despite the great improvement on YDFL development, the lasing performance can be diminish by photodarkening (PD) phenomenon, and many enforces has been carried out to minimize PD. Some report shows an improvement in the PD resistance due to Mg doping but with few details. So, in this work the influence of Mg and other co-dopants on photo induced absorption (PIA) of doped silica glasses are presented. Depends on preparation conditions a broad absorption around 270nm is observed or absent. The PIA intensity in all samples increases with X-ray irradiation time and saturates after around 100min. In only Mg doped silica glasses, the PIA intensity after 110min of X-ray irradiation increases with the Mg concentration, but there is no significant change in the spectrum shape. In the other hand, in Al or Yb co-doped samples, different bands appears, indicating the formation of other defects related to this two elements.