Zhang Heng, Ren Xudong, Yan Wenhua, Cheng Yuan, Zhou Hang, Gao Zhi, Luo Qin, Zhou Minkang, Hu Zhongkun
Opt Express. 2021 Sep 13;29(19):30007-30019. doi: 10.1364/OE.433968.
The temperature of atoms, coupled to several effects, plays an important role in high precision atom interferometry gravimeters. In this work, we present an ultra-cold Rb atom interferometry gravimeter, in which the atom source is produced by evaporative cooling in an all optical dipole trap to investigate the effects related to atom temperature. A condensate containing 4 × 10 atoms can be prepared within 3.2 s through an all-optical dipole trap composed of two reservoirs and a dimple. The fringe contrast of our atom interferometry gravimeter reaches up to 76(4)% due to the advantage of ultra-cold atom source even at a free evolution time of T=80 ms. A resolution of 6 μGal (1 μGal=1×10 m/s) after 3000 s integration time with a sampling rate of 0.25 Hz is achieved in this atom gravimeter. The relationship between the fringe contrast and the atom temperature in the atom gravimeter is studied; in addition, the wavefront aberration effect in the atom gravimeter is also investigated by varying the temperature of atoms.
原子温度与多种效应相关联，在高精度原子干涉重力仪中起着重要作用。在这项工作中，我们展示了一种超冷铷原子干涉重力仪，其中原子源通过在全光偶极阱中进行蒸发冷却产生，以研究与原子温度相关的效应。通过由两个储液器和一个凹坑组成的全光偶极阱，可在3.2秒内制备出包含4×10个原子的凝聚体。由于超冷原子源的优势，即使在自由演化时间T = 80毫秒时，我们的原子干涉重力仪的条纹对比度也能达到76(4)%。在该原子重力仪中，积分时间为3000秒、采样率为0.25赫兹时，实现了6微伽（1微伽 = 1×10米/秒²）的分辨率。研究了原子重力仪中条纹对比度与原子温度之间的关系；此外，还通过改变原子温度研究了原子重力仪中的波前像差效应。
