Suppression of photo-darkening by Ca additive in Yb-doped silica fiber

Researches on additive effects have been reported that phosphorous and cerium additives effectively reduce the photo-darkening (PD) effect in Yb-doped silica fiber. Lee et al. presented another solution to suppress PD by preventing Yb-Yb clustering in a fiber material using phosphate glass. In this work, a Yb-doped silica glass (YbZSG) and a Yb-Ca co-doped silica glass (YbCaZSG) for the core materials were fabricated by the zeolite method to get homogeneous dispersion of rare earth ions in silica glass.