Photodarkening in Yb-doped aluminosilicate fibers induced by 488 nm irradiation.
Photodarkening of Yb-doped aluminosilicate fibers by continuous wave 488 nm irradiation was investigated. The irradiation induced significant excess loss in the UV-visible spectroscopy (VIS) region in Yb-doped aluminosilicate fibers while pure aluminosilicate fibers showed negligible induced loss. Ultraviolet-VIS-near-infrared spectroscopy revealed an absorption peak at 220 nm in unexposed Yb-doped aluminosilicate fiber preforms. The observed peak was attributed to Yb-associated oxygen deficiency centers (ODCs) and proposed as a precursor of the photodarkening. The proposed model was supported by measurements on oxygen-loaded Yb-doped aluminosilicate fibers. In these, the photodarkening could be significantly reduced, which we attribute to a smaller number of ODCs following oxygen loading.
Yoo
S
S
Optoelectronics Research Centre, University of Southampton, UK. sey@orc.soton.ac.uk
Basu
C
C
Boyland
A J
AJ
Sones
C
C
Nilsson
J
J
Sahu
J K
JK
Payne
D
D