Photosensitivity and photoluminescence of Sn/Yb codoped silica o...

Sn/Yb codoped silica optical fiber preform is prepared by the modified chemical vapor deposition (MCVD) followed by the solution-doping method. Ultraviolet (UV) optical absorption, photoluminescence (PL) spectra under 978-nm laser diode (LD) pumping, and refractive index change after exposure to 266-nm laser pulses are obtained. There is only a little change in the PL spectra while a positive refractive index change up to 2\times10^{-4} is observed after 30-min exposure to 266-nm laser pulses. T