Optical properties of ytterbium/aluminium doped silica glasses

Several series of preform and fiber samples of Yb 2 O 3 -Al 2 O 3 -SiO 2 glass with finely-graded composition steps were prepared by MCVD and solution doping under well-defined conditions using both oxidizing and reducing atmospheres during preform collapse. Their optical properties, including absorption and emission behavior in the NIR/VIS/UV region, have been characterized and correlated with the detailed glass composition. The results present an overview of the property spectrum, which should contribute to the further development of laser fibers and the discussion and control of disturbing effects such as photodarkening.