An Optical Conveyor for Light-Atom Interaction

J. A. Sauer, Kevin Fortier, M. Mukai +3 more

D. Schrader, Stefan Kuhr, Wolfgang Alt +3 more

Georgy A. Kazakov, Dubey S., Famà F. +5 more

We report on our progress towards a continuously-operating active optical clock on the3P0→1S0transition of neutral87Sr or88Sr atoms. Our approach is based on a ring-cavity in which an optical conveyor carries a continuous stream of atoms along the cavity mode. We estimate the performance of our system by simulating the superradiant output from two counter-propagating cavity modes interacting with the atoms. The impact of the position-dependent light shifts, collisional decoherence and loss of atoms trapped within the optical conveyor are analysed.

K. Voutyras

In this work, we cool Rubidium atoms to the Doppler limit. After atoms were cooled, we use two purely optical traps, an Optical Dipole Trap (ODT) and a standing wave trap (optical conveyor) to transport them. We have optimized the performance of the standing wave trap and succeeded to slowly transport 105 traps and cools atoms to the surface of a nanophotonic sample located 5 mm from the loading point. We calibrated the required optical power during absorption imaging for the accurate and reproducible calculation of the number of trapped atoms. A 200 nm thin free-standing Silicon-Nitride slab waveguide was used to probe interactions between atoms and resonant light in the guided mode. The propagating mode has an evanescent tail that extends further than the physical dimensions of the waveguide. Bringing atoms to the resonant field can trigger interactions between light and atoms. We succeeded in coupling light in and out of the waveguide and built a dedicated imaging section for the transmission. Last, we performed a reference experiment to determine the response of the optical setup, without the presence of atoms at the proximity of the slab waveguide.

R. Mark Wilson

Xinchao Zhou, Tzu-Han Chang, Hikaru Tamura +1 more

Interfacing cold atoms with nanophotonic waveguides and resonators promises stronger atom-light interactions and leads to new paradigms for quantum optics. Here, we demonstrate coupling single atoms to a nanophotonic whispering-gallery-mode resonator using two different methods. The first one is an optical guiding technique that makes use of diffracted light from a nanophotonic waveguide to direct cold atoms to the evanescent region of the resonator. The second one is an optical conveyor-belt consisting of a moving optical lattice for controlled delivery of trapped atoms. Our demonstration enables new applications with scalable light-matter interface based on cold atoms coupled to nanophotonic circuits.