利用功率反馈排除晶格阱深波动导致的不稳定性后,主要研究了激光在空间或介质中传输的相位波动对晶格中超冷原子对比度的影响。通过晃动光晶格,人为引入可控相位噪声来测量其对原子对比度的影响,发现不同强度的相位噪声对实验结果的影响显著不同。但是小强度的相位噪声对超冷原子干涉对比度的影响并不明显,目前干涉对比度的测量精度并不能完全反映出激光相位对冷原子系统相干性的影响,说明这种空间构型光晶格在捕获超冷原子方面具有较高的稳健性。所提出的激光相位锁定技术可以有效减少晶格系统中的相位噪声,为未来空间构型光晶格中更精密的测量提供了基础。

After the instability caused by lattice depth fluctuation is eliminated using power feedback, the effect of the phase fluctuation for a laser propagating through space or other media on the interference contrast of ultracold atoms in an optical lattice is investigated. A man-made and tunable phase noise is introduced by shaking the optical lattice and its effect on atomic interference contrast ratio is measured. It is found that the phase noises with different intensities have different effects on the experimental results. However, the phase noise with a small intensity has a trivial effect on the interference contrast ratio of ultracold atoms. At present, the measurement accuracy of interference contrast ratio cannot fully show the influence of laser phase on the coherent property of a cold atomic system. This means that this kind of optical lattice with a spatial configuration possesses a good robustness in the capture of ultracold atoms. Furthermore, in order to improve the phase stability, a laser phase locking technique is proposed for the optical lattice with a spatial configuration, which can effectively reduce the phase noise in the lattice system and provide a basis for the future high precision measurements by an optical lattice with a spatial configuration.