Glass‐forming regions and enhanced 2.7 μm emission by Er³⁺ heavily doping in TeO₂–Ga₂O₃–R₂O (or MO) glasses

Abstract

Er3+‐doped fiber lasers operating at 2.7 μm have attracted increasing interest because of their various important applications; however, the intrinsic self‐terminating effect of Er3+ and the reliability of glass hosts hindered the development of Er3+‐doped fiber lasers. Herein, the glass‐forming regions of a series TeO2–Ga2O3–R2O (or MO) (R = Li, Na, and Rb; M = Mg, Sr, Ba, Pb, and Zn) glasses are predicted by the thermodynamic calculation method. On this basis, the physical and optical properties of TeO2–Ga2O3–ZnO (TGZ) glass are investigated in detail as an example. Under the excitation of 980 nm laser diode, the fluorescence intensity at 2.7 μm reaches a maximum in the heavily Er3+‐doped TGZ glass. By contrast, the accompanying near‐infrared fluorescence at 1.5 μm and upconversion green emissions at 528 nm and 546 nm are all effectively weaken. Furthermore, the lifetime gap between the 4I11/2 upper laser level and 4I13/2 lower laser level is sharply narrowed from 2.81 ms to 0.59 ms, which is beneficial to overcome the population conversion bottleneck. All results demonstrate that these newly developed ternary tellurite glass systems are promising candidates for near‐/mid‐infrared laser glass fiber, fiber amplifiers, and fiber lasers.

Enhanced 1.5 μm emission from Yb3+/Er3+ codoped tungsten tellurite glasses for broadband near-infrared optical fiber amplifiers and tunable fiber lasers

“…Good linear fitting implies that Er 3+ ions are uniformly distributed without phase separation and agglomeration in the present tungsten tellurite glasses. 18 …”

Preparation and characterizations of glasses in the TeO2–Ga2O3–M2O (M═Li, Na, K) systems

“…3,9,12 The glass forming domains of the ternaries are larger than predicted. 14 The exact boundaries of the glass forming areas depend on the technological conditions of sample preparation, among others on the purity of starting compounds and the changes of the melt composition during the melting process (due to evaporation of the constituents of the melt or contamination by the material of the crucible, e.g.). In this work, we tested the glass formation only in the TeO 2 -rich corner of the ternary diagram.…”

“…The influence of any admixture in the glass acting as a factor contributing to stabilization against devitrification must be admitted and it may be the reason why the determined glass forming areas of the ternary systems are larger than predicted. 14 However, we consider the contribution of adventitious Si to be negligible due to its very low concentration especially when compared to the main glass melt components content. However, it would certainly be interesting to verify in the future the glass formation using other crucibles.…”

“…13 Recently, the glass forming regions in ternary systems of TeO 2 -Ga 2 O 3 -M 2 O (M═Li, Na) were predicted but not confirmed experimentally. 14 In this work, we report on the glass formation in ternary systems of TeO 2 -Ga 2 O 3 -M 2 O (M═Li, Na, or K) prepared by rapid melting in SiO 2 crucibles. We delimited the corresponding glass forming areas and investigated the physicochemical properties of the prepared glasses.…”

“…The amorphous domain can be greatly increased by addition of alkali chloride, up to 60 mol% in the case of LiCl 13 . Recently, the glass forming regions in ternary systems of TeO 2 –Ga 2 O 3 –M 2 O (M═Li, Na) were predicted but not confirmed experimentally 14 …”