We present a compact, two-stage atomic beam source that produces a continuous, narrow, collimated and high-flux beam of rubidium atoms with sub-Doppler temperatures in three dimensions, which features very low emission of near-resonance fluorescence along the atomic trajectory. The atom beam source originates in a pushed two-dimensional magneto-optical trap (2D${}^{+}$ MOT) feeding a slightly off-axis three-dimensional moving optical molasses stage that continuously cools and redirects the atom beam. Near-resonance light from the 2D${}^{+}$ MOT and the push beam does not propagate to the output atomic trajectory due to a $10\degree$ bend in the atomic trajectory. The atomic beam emitted from the two-stage source has a flux up to $1.6(3)\times {10}^{9}atoms/s$, with an optimized temperature of $15.0(2)$~. This cold-atom beam source is appropriate for use in atom interferometers and clocks, where continuous operation eliminates dead time, the slow atom beam velocity (6_-16~m/s) improves sensitivity, the narrow 3D velocity distribution improves fringe contrast, and the low reabsorption of scattered light mitigates decoherence caused by the continuous cooling process.

中文翻译：

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高对比度原子干涉法的原子束源的三维冷却

我们提出了一个紧凑的两阶段原子束源，它产生连续，狭窄，准直且高通量的beam原子束，并在三个维度上具有亚多普勒温度，其特征是沿原子轨迹的近共振荧光发射极低。原子束源起源于推动的二维磁光阱（2D${}^{+}$MOT）送入稍微偏轴的三维移动光学糖蜜阶段，该阶段会不断冷却并重新引导原子束。来自2D的近共振光${}^{+}$由于原子轨迹的$ 10 \°$弯曲，MOT和推梁不会传播到输出原子轨迹。从两级源发出的原子束的通量高达$1.6（3）\times {10}^9\mathrm{一种}ŤØ米s/s$，最佳温度为 $15.0（2）$〜。此冷原子束源是适合于在原子干涉仪和时钟使用，其中连续操作消除死区时间，缓慢原子光束速度（6 _- 16〜米/秒）提高了灵敏度，窄三维速度分布改善条纹对比度，和散射光的低重吸收可减轻由连续冷却过程引起的退相干。