Precise imaging is instrumental to ultracold atomic technology both for precision measurements and for quantum simulation of many-body physics. Comparing with regular imaging techniques, holographic imaging based on phase-retrieval extends the measurement observables from real to complex numbers and therefore supports single-shot spectroscopic measurements even in presence of atomic column density uncertainty. The holographic technique also enables high spatial resolution without limiting the depth of view. Furthermore, by encoding local atomic optical response into delocalized interference fringes in the far field, the camera pixels are more efficiently exploited to support a measurement dynamic range beyond those typically achievable in absorption images. So far, the highly desirable features listed above are rarely exploited in atomic physic. Among various factors that prevent accurate implementation of holographic techniques to cold atoms is the fact that cold atomic samples are usually thermal and tend to be spatially ''featureless'', invalidating a class of phase-retrieval algorithms in other fields based on edge-detections. We note that when the atomic samples are subjected to plane or spherical wave illuminations, the coherent forward emission by the smooth and localized samples are naturally decomposed into Gaussian modes. We exploit this feature and develop a systematic Gaussian-packet method to resolve the optical response of cold atomic ensembles. Based on the new method, we demonstrate ''complex'' spectroscopic imaging of atomic ensemble capable of simultaneously resolving atomic column density and spatial-dependent light shift, both near the photon shot noise limit. We also investigate the potential of the new method for imaging atomic samples with high optical depth where regular absorption images would lead to poor statistics.
|Presenter name||Xing Huang|
|online poster URL||https://ultracontrol.fudan.edu.cn/wonference/list.htm|
|How will you attend ICAP-27?||I am planning on virtual registration for online attendance|