Influences of Mn2+ ions, and Mn2+–Yb3+ dimer on the optical band gaps and bandwidth flatness of near-infrared emissions of Ho3+/Tm3+, Ho3+/Tm3+/Yb3+ co-doped calcium aluminosilicate glasses

The effect of MnCO3 on the gain coefficient for the 4I13/2 → 4I15/2 transition of Er3+ ions and near-infrared emission bandwidth flatness of Er3+/Tm3+/Yb3+ co-doped barium zinc silicate glasses

“…The main reason for the increase in NIR emission intensity of Er 3+ /Yb 3+ -co-doped peaks at ∼1542 nm can be attributed to the combination between Yb 3+ and Mn 2+ ions in the MnCO 3 compound leading to the formation of Mn 2+ –Yb 3+ dimers 13,32 contributing to the energy transfer (ET) to the 4 I 13/2 → 4 I 15/2 transition of Er 3+ ions. 13,23 The formation of an Mn 2+ –Yb 3+ dimer can be interpreted with the result shown in Fig. 3, where the Er 3+ and Yb 3+ concentrations are unchanged when the concentration of the MnCO 3 compound increases from 2 up to 4 mol%, and the NIR emission intensity of the Er 3+ /Yb 3+ -co-doped peaks at ∼1542 nm under the excitation of 980 nm LD was significantly increased.…”

“…19,23 The obtained results indicated that the NIR bandwidth flatness of Tm 3+ -doped, Ho 3+ -doped, Tm 3+ /Ho 3+ -co-doped, and Ho 3+ /Tm 3+ /Yb 3+ co-doped glasses was significantly improved by the presence of Mn 2+ ions and an Mn 2+ –Yb 3+ dimer in the host glasses. 13,14,23…”

“…24,25 In the experiment in this study, the SiO 2 , ZnO, TiO 2 , BaO, Er 2 O 3 , Tm 2 O 3 , and Yb 2 O 3 raw material mixtures have melting points greater than 1580 °C. However, we chose the material melting temperature of 1580 °C 23 at which these material mixtures are melted enough to form glasses. 23,24 In the next step, the melted mixtures were poured into a mold and quenched on the surface of a stainless steel plate to form the raw glass.…”

“…However, we chose the material melting temperature of 1580 °C 23 at which these material mixtures are melted enough to form glasses. 23,24 In the next step, the melted mixtures were poured into a mold and quenched on the surface of a stainless steel plate to form the raw glass. To increase the mechanical strength and remove thermal strain from the raw glass, all raw glass samples were annealed at ∼500 °C for a continuous period of 12 hours.…”

“…18–22 In our previous studies, 23,24 we investigated, calculated, and reported solutions to widen the bandwidth as well as to enhance the near-infrared bandwidth flatness of Tm 3+ -doped, Ho 3+ -doped, Tm 3+ /Ho 3+ -co-doped, and Ho 3+ /Tm 3+ /Yb 3+ -co-doped glasses. 19,23 The obtained results indicated that the NIR bandwidth flatness of Tm 3+ -doped, Ho 3+ -doped, Tm 3+ /Ho 3+ -co-doped, and Ho 3+ /Tm 3+ /Yb 3+ co-doped glasses was significantly improved by the presence of Mn 2+ ions and an Mn 2+ –Yb 3+ dimer in the host glasses. 13,14,23…”