Nondestructive Phase Shifting Imaging of Cold Atoms

We propose a nondestructive phase shifting imaging for cold atoms by using a Gaussian beam and accompanying with phase shifting interferometry in a Mach-Zehnder interferometer [1-2]. This imaging scheme could require no imaging lens. Hence, aberration associated with it is completely eliminated and mechanical focusing can be avoided. Compared to the common single-beam nondestructive means [3], our proposed scheme allows energy per probe pulse delivered to the cold samples lowered by almost three orders of magnitude due to signal enhancement inherently provided in the two-beam configuration. In this meeting, we will describe the working principle and show our experimental realization of this novel nondestructive detection means for in-situ imaging on the rubidium-87 atoms confined in a magneto-optical trap. Besides, we will present measured data to demonstrate the focusing capability provided in this scheme as well, though no imaging lens is used.\\[4pt] [1] Tzu-Ping Ku\textit{ et al}., Opt. Express \textbf{19}, 3730 (2011).\\[0pt] [2] Chih-Yuan Huang \textit{et al}., J. Opt. Soc. Am. B \textbf{31}, 87 (2014).\\[0pt] [3] M. R. Andrews \textit{et al}., Science \textbf{273}, 84 (1996).