We investigated room-temperature pulsed lasing in heavily doped Fe:ZnSe single crystals. The active elements were pumped by a Q-switched Cr3+:Yb3+:Ho3+:YSGG laser operating at 2.87 μm. Our results show that the generation of short laser pulses has a deep high-frequency modulation associated with relaxation dynamics in Fe:ZnSe. The lasing regime obtained in this study provides a straightforward way to generate mid-IR single nanosecond pulses at moderate pump energies. Moreover, we found a relation between the lasing pulse duration and the concentration of Fe2+ doping ions, and we experimentally demonstrated pulse shortening in heavily doped active crystals. Single-pulse lasing with an FWHM pulse duration of ∼2.8 ns was achieved in ZnSe crystals doped with 2.3 · 1019 cm-3 Fe2+ ions. The demonstrated single-pulse lasing regime is applicable for seeding high-power mid-IR laser systems.

中文翻译：

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重掺杂 Fe:ZnSe 中的单纳秒脉冲激光

我们研究了重掺杂 Fe:ZnSe 单晶中的室温脉冲激光。活性元素由 Q 开关 Cr3+:Yb3+:Ho3+:YSGG 激光器泵浦，激光器工作在 2.87 μm。我们的结果表明，短激光脉冲的产生具有与 Fe:ZnSe 弛豫动力学相关的深度高频调制。本研究中获得的激光状态提供了一种直接的方法，可以在中等泵浦能量下产生中红外单纳秒脉冲。此外，我们发现了激光脉冲持续时间与 Fe2+ 掺杂离子浓度之间的关系，并且我们通过实验证明了重掺杂活性晶体中的脉冲缩短。在掺杂有 2.3 · 1019 cm-3 Fe2+ 离子的 ZnSe 晶体中实现了 FWHM 脉冲持续时间约为 2.8 ns 的单脉冲激光。