Effective mitigation of photo-darkening By Na+ ions doping in Yb-doped fibers

In this work, Na
⁺
ions doping into the Yb-doped fiber was proposed to improve the photo-darkening resistance. The results show that the photo-darkening induced excess loss at 702 nm was 37.26dB/m at equilibrium state. More than 50% excess loss was reduced comparing to Yb-doped fiber without Na+ ions.