A multi-position disordered Er³⁺:Gd₂SrAl₂O₇ single crystal was grown by the Czochralski method. Room temperature polarized spectral properties of the crystal were investigated in detail. The Judd–Ofelt theory was applied to analyze the polarized absorption spectra. The peak stimulated emission cross-sections of the ⁴I_13/2→⁴I_15/2 transition reach 0.79 ×10⁻²⁰ and 1.25×10⁻²⁰ cm² for σ and π polarizations, respectively. The gain curves are flat with full widths at half the maximum larger than 60 nm. Fluorescence lifetimes of the ⁴I_13/2 multiplet for Er³⁺ ions were fitted to be 4.93 ms and 3.48 ms from measured fluorescence decay curves for bulk and powder samples, respectively. The results show that the Er³⁺:Gd₂SrAl₂O₇ crystal may be a potential gain medium for a 1.55 µm laser with low pumping threshold.

中文翻译：

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Er ³⁺：Gd ₂ SrAl ₂ O ₇晶体的偏振光谱性质

通过切克劳斯基方法生长多位置无序的Er ³⁺：Gd ₂ SrAl ₂ O ₇单晶。详细研究了晶体的室温偏振光谱特性。Judd-Ofelt理论被用于分析偏振吸收光谱。峰值刺激的发射截面⁴我_13/2 → ⁴我_15/2过渡到达0.79×10 ^-20和1.25×10 ^-20厘米²为σ和π极化，分别。增益曲线是平坦的，具有大于60 nm的最大值的一半的全宽度。⁴ I的荧光寿命Er ³⁺离子的_13/2多重_峰拟合为分别从散装和粉末样品的测得的荧光衰减曲线分别为4.93 ms和3.48 ms。结果表明，对于泵浦阈值低的1.55 µm激光器，Er ³⁺：Gd ₂ SrAl ₂ O ₇晶体可能是潜在的增益介质。