In optically pumped lasers, heat generated by the quantum defect causes detrimental fluctuations in the output mode, frequency, and power. Common heat-mitigation techniques use bulky mechanical coolers that introduce vibrations, leading to laser frequency and amplitude noise. Here, we present a radiation-balanced fiber laser, optically cooled by anti-Stokes fluorescence (ASF). The gain medium is a silica fiber with a 21-µm-diameter core doped with 2.06 wt. % ${{\rm Yb}^{3 +}}$ and co-doped with ${{\rm Al}_2}{{\rm O}_3}$ and F- to reduce concentration quenching. The laser was core-pumped at 1040 nm to create both gain at 1065 nm and ASF cooling at atmospheric pressure. We demonstrate a maximum output power of 114 mW with a slope efficiency of 41% while maintaining near-zero average temperature change. This result could enable the development of fiber lasers with unprecedented coherence and stability.

中文翻译：

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辐射平衡石英光纤激光器

在光泵浦激光器中，量子缺陷产生的热量会导致输出模式、频率和功率的有害波动。常见的散热技术使用笨重的机械冷却器，这些冷却器会引入振动，从而导致激光频率和振幅噪声。在这里，我们提出了一种辐射平衡光纤激光器，通过反斯托克斯荧光 (ASF) 进行光学冷却。增益介质是一根直径为 21 µm 的石英光纤，掺杂了 2.06 wt. % ${{\rm Yb}^{3 +}}$和${{\rm Al}_2}{{\rm O}_3}$共掺杂和 F- 以减少浓度猝灭。激光器在 1040 nm 处进行核心泵浦，以在 1065 nm 处产生增益并在大气压下产生 ASF 冷却。我们展示了 114 mW 的最大输出功率和 41% 的斜率效率，同时保持接近零的平均温度变化。这一结果可以使光纤激光器的发展具有前所未有的相干性和稳定性。