Basic and Peculiar Properties of Chromium–Magnesium Co-Doped YAS-Based Optical Fibers

The basic and peculiar properties of new-type chromium (Cr) and magnesium (Mg) co-doped yttrio–alumino–silicate-based optical fibers, fabricated through the classic modified chemical vapor deposition method employed in conjunction with solution-doping technique, are addressed, with most of attention being paid to impact of Cr/Mg co-doping strength. The electron probe microanalysis, Raman, optical absorption, and fluorescence [at excitation at different wavelengths, spanning visible to near-infrared (NIR)] spectra’ measurements are performed for clarifying overall state-of-the-art of the fibers. Their most remarkable features are demonstrated to be pronounceable fluorescence in NIR (beyond 1
$\mu \text{m}$
) and as well pronounceable bleaching effect under the action of 1-
$\mu \text{m}$
light, both adherent to the presence of Cr
⁴⁺
ions.