In this paper, the glass network of a newly developed bismuthate glass was adjusted and analyzed by changing the Al₂O₃ content, thus effectively increasing the doping concentration of Tm³⁺. The fundamental physical and thermal properties including density, molar volume, refractive indices, and characteristic temperatures were systematically investigated, suggesting the B₂O₃/Al₂O₃ anomaly ratio of the prepared host glass is 35%/10%. Various glass network units were found in the host glasses, so that the flexibility of the glasses was enhanced, which is favorable for highly and homogeneously doping of Tm³⁺ ions. A highly Tm³⁺-doped bismuthate glass with a concentration of 20.5 × 10²⁰ ions/cm³ was prepared without quenching. Radiative parameters of the presented glass were determined from absorbance spectra. Moreover, relatively large emission cross-section (5.29 × 10⁻²¹ cm²) and gain coefficient (10.87 cm^-1) were achieved in the prepared highly Tm³⁺-doped bismuthate glass. Finally, the microparameters for energy transfer processes were calculated by a spectral overlap method. Results show that the presented highly Tm³⁺-doped bismuthate glass has ideal potential for high gain fibers in ∼2 µm band.

中文翻译：

---

基于 Al2O3 调节的高 Tm3+ 掺杂铋酸盐玻璃中的~2 μm 荧光和能量转移特性

本文通过改变Al ₂ O ₃含量对新开发的铋酸盐玻璃的玻璃网络进行了调整和分析，从而有效提高了Tm ³⁺的掺杂浓度。系统研究了基本物理和热性能，包括密度、摩尔体积、折射率和特征温度，表明所制备的主体玻璃的 B ₂ O ₃ /Al ₂ O ₃异常比为 35%/10%。在主体玻璃中发现了各种玻璃网络单元，从而增强了玻璃的柔韧性，有利于Tm ³⁺离子的高度均匀掺杂。一个高 Tm制备浓度为 20.5 × 10 ²⁰离子/cm ^{3 的3+}掺杂铋酸盐玻璃，无需淬火。所呈现玻璃的辐射参数由吸收光谱确定。此外，在制备的高 Tm ³⁺掺杂的铋酸盐玻璃中实现了相对大的发射截面（5.29 × 10 ^-21 cm ²）和增益系数（10.87 cm ^-1）。最后，通过光谱重叠法计算了能量转移过程的微观参数。结果表明，所提出的高 Tm ³⁺掺杂的铋酸盐玻璃具有理想的潜力，可用于 2 µm 波段的高增益光纤。