Abstract A vibration-free, optical cooling refrigerator may imply revolutionary applications in different fields, therefore it is vital to explore new materials suitable for laser cooling below the cryogenic temperature. Here we demonstrate that the Yb3+-doped LuLiF4 crystal is a promising material that could reach the cryogenic temperature limit (123 K) or even lower. With the doping concentration of 7.5%, the Yb3+-doped LuLiF4 crystal can be optically cooled down from the room temperature to 141.8 K in a double-pass setup. Provided with better purity and multiple-pass of laser cooling in the crystal, the temperature limit can even reach as low as 89 K for the 7.5% Yb3+-doped LuLiF4 crystal, thus making it a competitive candidate for laser cooling below the cryogenic temperature.

中文翻译：

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用于光学制冷的 Yb3+ 掺杂 LuLiF4 单晶的表征

摘要 一种无振动的光学冷却冰箱可能意味着在不同领域的革命性应用，因此探索适用于低温以下激光冷却的新材料至关重要。在这里，我们证明了 Yb3+ 掺杂的 LuLiF4 晶体是一种很有前途的材料，可以达到低温极限 (123 K) 甚至更低。在 7.5% 的掺杂浓度下，Yb3+ 掺杂的 LuLiF4 晶体可以在双通道设置中从室温光学冷却到 141.8 K。由于具有更好的纯度和晶体中激光冷却的多次通过，7.5% Yb3+掺杂的 LuLiF4 晶体的温度极限甚至可以低至 89 K，从而使其成为低温以下激光冷却的竞争候选者。