Energy transfer enhanced near-infrared spectral performance in bismuth/erbium codoped aluminosilicate fibers for...

The energy transfer processes between bismuth active centers (BACs) and Er³⁺ in Bi/Er codoped fiber (BEDF) are investigated and, with clear experimental evidence, observed for the first time. Under 980 nm pumping, we observed an energy transfer from Er³⁺ to BAC-Al in BEDF, evidenced by the enhanced NIR emission and lifetime when compared with a bismuth doped fiber (BDF). Under 830 nm pumping, the spectral performance of Er³⁺ in BEDF is found to benefit from BAC-Al→Er³⁺, evidenced by the notable increase in NIR emission, lifetime, and gain. The observations confirm that proper codoping of Er in Bi-doped fibers could introduce significant changes to emission through ET processes and provides a promising strategy for improving spectral performance over the 1000-1600 nm range.