STIR-Physics: Cold Atoms and Nanocrystals in Tapered Nanofiber and High-Q Resonator Potentials

Jeonghan Lee, Jeffrey A. Grover, Jennifer E. Hoffman +13 more

Tara Hennessy, Thomas Busch

We describe theoretically a setup in which a tapered optical nanofiber is introduced into an optical lattice potential for cold atoms. First, we consider the disturbance to the geometry of the lattice potential due to scattering of the lattice lasers from the dielectric fiber surface and show that the resulting distortion to the lattice can be minimized by placing the fiber at an appropriate position in the lattice. We then calculate the modifications of the local potentials that are achievable by transmitting off-resonant light through the fiber. The availability of such a technique holds the potential to deterministically create and address small well-defined samples of atoms in the evanescent field of the tapered nanofiber.

S R Krishnapriya, Tridib Ray, Síle Nic Chormaic

Michael Morrissey, Kieran Deasy, Yuqiang Wu +2 more

We present a novel technique for measuring the characteristics of a magneto-optical trap (MOT) for cold atoms by monitoring the spontaneous emission from trapped atoms coupled into the guided mode of a tapered optical nanofiber. We show that the nanofiber is highly sensitive to very small numbers of atoms close to its surface. The size and shape of the MOT, determined by translating the cold atom cloud across the tapered fiber, is in excellent agreement with measurements obtained using the conventional method of fluorescence imaging using a charge coupled device camera. The coupling of atomic fluorescence into the tapered fiber also allows us to monitor the loading and lifetime of the trap. The results are compared to those achieved by focusing the MOT fluorescence onto a photodiode and it was seen that the tapered fiber gives slightly longer loading and lifetime measurements due to the sensitivity of the fiber, even when very few atoms are present.

Jérémy Berroir, Tridib Ray, Neil Corzo +4 more

Nanoscale waveguides provide a tight transverse confinement of guided light, not limited by the Rayleigh range, allowing enhanced atom-photon interaction over a large sample. In our system, we interface a tapered optical nanofiber with an ensemble of cold Cesium atoms in an ultra-high vacuum chamber, trapped in a 1D lattice geometry using the evanescent field around the nanofiber.

Pablo Solano, S. L. Rolston, Luis A. Orozco +2 more