Acceleration of photodarkening measurements in Yb-doped fibers by enhanced temperatures

The probe transmission at 633 nm was plotted during core pumping with 300 mW (pump wavelength 976 nm) what established an inversion of about 0.47 in the short fiber pieces of some centimeters. The results are discussed also in comparison to measurements at room temperature in dependence on the inversion, and the suitability of the suggested method of PD characterization at enhanced temperatures is evaluated for fibers with low Yb doping.