Local structure analyses around Er(3+) in Er-doped fibers with Al co-doping.

The local structure around Er(3+) in Er-doped optical fiber (EDFs) was explored by X-ray absorption fine structure (XAFS) measurements. Using several new approaches such as a novel sample preparation, we successfully measured the XAFS. The intensities near the 8.36 keV peaks were observed for the first time using X-ray Absorption Near Edge Structure (XANES) analysis. The intensities increased in the order of Er, Er(2)O(3), and EDF samples, indicating that Er(3+) in the EDFs existed as an oxide state. Extend X-ray Absorption Fine Structure (EXAFS) analysis also showed that the oxygen coordination number of Er(3+) increased as the Al concentration increased and that the Er-O distances of EDF with Al co-doping is longer than that of EDF without Al co-doping.