Spatial Heterodyne Imaging of Trapped Atoms

G Müller, Andreas Wicht, R.-H. Rinkleff +1 more

Steve Kadlecek, Jennifer Sebby-Strabley, Raymond Newell +1 more

We demonstrate a new method for nondestructive imaging of laser-cooled atoms. This spatial heterodyne technique forms a phase image by interfering a strong reference laser beam with a weak probe beam that passes through the cold atom cloud. The figure of merit equals or exceeds that of phase-contrast imaging, and the technique can be used over a wider range of spatial scales. We show images of a dark-spot magneto-optic trap taken with imaging fluences as low as 61 pJ/cm(2) at a detuning of 11? , resulting in 0.0004 photons scattered per atom.

A. M. Herkommer, H. J. Carmichael, Wolfgang P. Schleich

Jasper Smits, Allard P. Mosk, P. van der Straten +2 more

We present a dispersive imaging method for trapped quantum gases based on digital off-axis holography. Both phase delay and intensity of the probe field are determined from the same image. Due to the heterodyne gain inherent to the holographic method, it is possible to retrieve the phase delay induced by the atoms at probe beam doses two orders of magnitude lower than phase-contrast imaging methods. Using the full field of the probe beam, we numerically correct for image defocusing.

T. A. Savard

John Thomas