Sub-Micron Optical Tweezers for the Study of Ultra-Cold Atoms – Niels Bohr Institute - University of Copenhagen

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Sub-Micron Optical Tweezers for the Study of Ultra-Cold Atoms

Recent advances in CCD technology and the availability of high numerical-aperture aspheric lenses provide the capability of directly observing the microscopic quantum phenomena of atoms.


In this talk I will describe our new atomic tweezers setup aiming at manipulation and detection of the microscopic dynamics of atoms. In principle, the optical design is similar to  microscope incorporated optical-tweezers that are commonly used today by biologists. However, we needed to incorporate our  atom-optics tweezers and microscope into a laser cooling and trapping apparatus. Specifically, We use a high-numerical aperture lens to focus an off-resonant laser beam to form an optical-dipole trap with sub-micron feature size. Atoms are loaded into the trap from a MOT cloud and cooled using standard polarization gradient cooling techniques. We form an image of the trapped atoms, using the same lens, as they are excited by a separate on-resonance detection beam. I will present preliminary results of in-situ fluorescence imaging of dense samples in our micro trap.