Raman-induced resonance imaging of trapped atoms

T. A. Savard, S. R. Granade, Kenneth M. O’Hara +2 more

We apply Raman-induced resonance imaging techniques to determine, with a spatial resolution of 12 $\ensuremath{\mu}\mathrm{m},$ the size of a cloud of atoms in a magneto-optical trap and the location of the centroid with respect to the magnetic-field zero point. These experiments provide a starting point for developing much higher-resolution resonance imaging methods for cold trapped atoms.

Humio Inaba

Eduardo Uruñuela, Maximilian Ammenwerth, Pooja Malik +4 more

High-bandwidth, fiber-based optical cavities are a promising building block for future quantum networks. They are used to resonantly couple stationary qubits such as single or multiple atoms with photons routing quantum information into a fiber network at high rates. In high-bandwidth cavities, standard fluorescence imaging on the atom-cavity resonance line for controlling atom positions is impaired since the Purcell effect strongly suppresses all-directional fluorescence. Here, we restore imaging of $^{87}\mathrm{Rb}$ atoms strongly coupled to such a fiber Fabry-P\'erot cavity by detecting the repumper fluorescence which is generated by continuous and three-dimensional Raman sideband cooling. We have carried out a detailed spectroscopic investigation of the repumper-induced differential light shifts affecting the Raman resonance, dependent on intensity and detuning. Our analysis identifies a compromise regime between imaging signal-to-noise ratio and survival rate, where physical insight into the role of dipole-force fluctuations in the heating dynamics of trapped atoms is gained.

Stephen J. Kadlecek, Jennifer Sebby-Strabley, Nathan Harrison +1 more

Gunnar Tackmann

Raman interferometry with free-falling and trapped atoms

M. S. Shahriar, Philip Hemmer

We have used a laser-induced resonance Raman transition between the ground-state hyperfine sublevels in a sodium atomic beam to excite individual dressed states of the microwave-spin hyperfine transition. In addition, we have used the microwave interaction to excite the Raman trapped state. Extension of this technique to mm waves or to the far infrared may lead to applications such as mm-wave-beam steering and holographic image conversion.