Local structure analyses around Er 3+ in Er-doped fiber with Al co-doping

The local structure around Er3+ 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, Er2O3, and EDF samples, indicating that Er3+ in the EDFs existed as an oxide state. Extend X-ray Absorption Fine Structure (EXAFS) analysis also showed that the oxygen coordination number of Er3+ increased as the Al concentration increased and that the Er-O distances of EDF with Al codoping is longer than that of EDF without Al co-doping.