Microlenses Offer Atom Interferometers

A team at Universität Hannover in Germany has produced interferometer structures for atoms by focusing the near-IR output of a Ti:sapphire laser through arrays of microlenses to generate patterns of optical dipole potentials. The work, which appeared in the Nov. 25 issue of Physical Review Letters, promises to enable the development of miniaturized sensors based on atom interferometry.

Arrays of cylindrical microlenses patterned in fused silica focused 360 mW of the red-detuned output of the laser into a series of waveguides, forming a 42° beamsplitter and structures for Mach-Zehnder and Michelson interferometers. A CCD camera monitored the passage of ultracold ⁸⁵Rb atoms through the structures by fluorescence imaging.