Photodarkening in Yb-doped Al-silicate fibers: Investigation, modelling and mitigation

In this paper we review our work on study of Photodarkening in Yb-doped Al-silicate base. We propose a measurement set-up and we investigate the possibility of Photodarkening mitigation by using visible light photons. We also report measurement of excited-state-absorption from excited Yb ions that plays a fundamental role in the photodarkening phenomenon.