Atomic interferences and the measurement process

Gombojav O. Ariunbold, Vladimir A. Sautenkov, Marlan O. Scully

The conventional method to measure atomic interference is usually based on incoherent processes which can be scaled by nano or microseconds. However, atomic interference may be studied in association with coherent process such as superfluorescence. Producing superfluorescent picosecond pulses in 87Rb vapor pumped by ~100 fs laser pulses, we report an observation of quantum beat due to D-lines. The relative delay of the superfluorescent pulses is measured by the streak camera with picosecond time resolution, as a function of time interval between input pulses, which also enables us to study atomic interference.

Jing Wang, Junze Tong, Wenbin Xie +3 more

When the initial size of an atom cloud in a cold atom interferometer is negligible compared to its size after free expansion, the interferometer is approximated to a point-source interferometer and is sensitive to rotational movements by introducing an additional phase shear in the interference sequence. This sensitivity on rotation enables a vertical atom-fountain interferometer to measure angular velocity in addition to gravitational acceleration, which it is conventionally used to measure. The accuracy and precision of the angular velocity measurement depends on proper extraction of frequency and phase from spatial interference patterns detected via the imaging of the atom cloud, which is usually affected by various systematic biases and noise. To improve the measurement, a pre-fitting process based on principal component analysis is applied to the recorded raw images. The contrast of interference patterns are enhanced by 7-12 dB when the processing is present, which leads to an enhancement in the precision of angular velocity measurements from 6.3 μrad/s to 3.3 μrad/s. This technique is applicable in various instruments that involve precise extraction of frequency and phase from a spatial interference pattern.

Evgeniĭ E. Nikitin, M. Ya. Ovchinnikova

Evgeny B. Alexandrov, М. П. Чайка, Gennadij I. Khvostenko

J. Wang, Bangcheng Han, L. Zhang +2 more

Atom interferometer gravity gradient measurement instrument has a very high measuring resolution when atomic interference of gravity gradient experiments, the first to obtain two atoms using a magneto-optical trap, after throwing or whereabouts and realization of double groups of interference in operation, during the process of the experiment on two-atom fountain behind the speed of synchronization is the prerequisite of implementation measure, In this paper, an experimental method for adjusting the up-throw velocity of a two-atom fountain is introduced. The uniformity of up-throw velocity of a two-atom fountain is achieved by utilizing an optical beam expanding tube of a cooling laser and a geomagnetic compensation coil, which can enhance the detection noise of the atomic interference gravity gradiometer.