Barium gallo-germanate glasses co-activated with Cr3+/Er3+ and Cr3+/Er3+/Ln3+ (Ln = Yb, Ho) for near-infrared luminescence applications

Near-infrared luminescence properties of barium gallo-germanate glasses co-activated with Cr 3+ /Er 3+ and Cr 3+ /Er 3+ /Ln 3+ (Ln = Yb, Ho) have been studied for the first time. Compared to Cr 3+ /Er 3+ co-doped sample, near-infrared emission of Er 3+ at 1534 nm in Cr 3+ /Yb 3+ /Er 3+ glass is enhanced under direct excitation of Cr 3+ at 600 nm. For Cr 3+ /Er 3+ /Ho 3+ glass, luminescence quenching of Er 3+ and enhancement of Ho 3+ at 2000 nm is quite well observed. Based on spectra and decays, the energy transfer processes Cr 3+ → Yb 3+ → Er 3+ and Cr 3+ → Er 3+ → Ho 3+ with their efficiencies equal to nearly 55% were identified. The presence of energy transfer processes was also confirmed using the excitation spectra measured under selective monitoring emission wavelengths. The results obtained for barium gallo-germanate glasses co-activated with Cr 3+ /Yb 3+ /Er 3+ and Cr 3+ /Er 3+ /Ho 3+ are promising for near-infrared luminescence applications.