Enhanced effect of Er3+ ions on 2.0 and 2.85 μm emission of Ho3+/Yb3+ doped germanate-tellurite glass

Abstract We report what we believe is the first demonstration of the enhanced Ho 3+ 2.0 μm (2.1 times) and 2.85 μm (2.6 times) emission by addition of Er 3+ in the Ho 3+ /Yb 3+ co-doped germanate-tellurite (GT) glass with optimized extra-low hydroxyl content ∂ O H − (0.118 cm −1 ). Meanwhile, enhanced 2.0 and 2.85 μm emission cross-sections (5.78 × 10 −21 and 17.9 × 10 −21  cm 2 ) can be approximately increased 1.5 times higher, respectively. The enhanced 2.0 and 2.85 μm emission upon excitation of a conventional 980 nm laser diode are investigated by the analysis of energy transfer. In addition, the energy transfer mechanism and coefficient (C DA ) from Yb 3+ to Ho 3+ and Er 3+ to Ho 3+ have been investigated in detail. Our results indicate that Ho 3+ /Er 3+ /Yb 3+ triply-doped GT glass is a promising material for 2.0 μm and 3 μm fiber laser.