The kinetics of the electronic transitions within the f-shell of Dy3+ ions were studied with monitoring near- and mid-IR luminescence decay under pulsed laser excitation at 1.3 µm. The luminescence decay curves were found to be profoundly non-exponential in all bands in the range between 1.3-5.5 µm. Such behavior is attributed to cross-relaxation and up-conversion processes dominating in relaxation of Dy3+ ions from the laser-excited multiplet 6H9/2+6F11/2. We suggest that strong collective phenomena occurring under relatively low concentrations are due to anomalous clustering of Dy3+ ions. The cross-relaxation enables an efficient population of 6H13/2 and 6H11/2 multiplets, offering this material as an active medium for a 3-µm and 4.3-µm lasers.

中文翻译：

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Dy 掺杂卤化银在近红外和中红外的集体现象

通过在 1.3 µm 脉冲激光激发下监测近红外和中红外发光衰减，研究了 Dy3+ 离子 f 壳层内的电子跃迁动力学。发现发光衰减曲线在 1.3-5.5 µm 范围内的所有波段中都非常非指数。这种行为归因于交叉弛豫和上转换过程，这在来自激光激发的多重态 6H9/2+6F11/2 的 Dy3+ 离子弛豫中占主导地位。我们认为在相对低浓度下发生的强烈集体现象是由于 Dy3+ 离子的异常聚集。交叉弛豫可实现 6H13/2 和 6H11/2 多重峰的有效填充，使这种材料可用作 3-µm 和 4.3-µm 激光器的活性介质。