Recent advances in power scaling of fiber lasers are hindered by the thermal issues, which deteriorate the beam quality. Anti-Stokes fluorescence cooling has been suggested as a viable method to balance the heat generated by the quantum defect and background absorption. Such radiation-balanced configurations rely on the availability of cooling-grade rare-earth-doped gain materials. Herein, we perform a series of tests on a ytterbium-doped ZBLAN optical fiber to extract its laser cooling-related parameters and show that it is a viable laser cooling medium for radiation-balancing. In particular, a detailed Laser Induced Modulation Spectrum (LITMoS) test is performed to highlight the transition of this fiber to the cooling regime as a function of the pump laser wavelength. Numerical simulations support the feasibility of a radiation-balanced laser, but highlight that practical radiation-balanced designs are more demanding on the fiber material properties, especially on the background absorption, than are solid-state laser cooling experiments.

中文翻译：

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作为辐射平衡激光器平台的掺镱ZBLAN光纤的激光冷却特性

光纤激光器功率缩放的最新进展受到热问题的阻碍，这会降低光束质量。反斯托克斯荧光冷却已被建议作为平衡量子缺陷和背景吸收产生的热量的可行方法。这种辐射平衡配置依赖于冷却级稀土掺杂增益材料的可用性。在此，我们对掺镱 ZBLAN 光纤进行了一系列测试，以提取其激光冷却相关参数，并表明它是一种可行的辐射平衡激光冷却介质。特别是，进行了详细的激光诱导调制光谱 (LITMoS) 测试，以突出该光纤作为泵浦激光波长函数的冷却状态的转变。数值模拟支持辐射平衡激光器的可行性，