Deterministic Loading of Individual Atoms to a High-Finesse Optical Cavity

Individual laser-cooled atoms are delivered on demand from a single atom magneto-optic trap to a high-finesse optical cavity using an atom conveyor. Strong coupling of the atom with the cavity field allows simultaneous cooling and detection of individual atoms for time scales exceeding 15 s. The single atom scatter rate is studied as a function of probe-cavity detuning and probe Rabi frequency, and the experimental results are in qualitative agreement with theoretical predictions. We demonstrate the ability to manipulate the position of a single atom relative to the cavity mode with excellent control and reproducibility.

Figure 1

A single atom MOT is formed 8.5 mm away from the optical cavity. The atom is loaded into an atom conveyor and then transported to the cavity mode. Inside the cavity, the atom is cooled via cavity-assisted cooling driven by counterpropagating probe beams.

Figure 2

The fluorescence signal collected from the high-gradient MOT with an exposure time of 500 ms per data point. Discrete steps indicate individual atoms captured or lost from the MOT. The inset shows a histogram of the integrated fluorescence signal of 0—5 trapped atoms.

Figure 3

Detected cavity emission signal vs time. In (a)–(d), the cavity emission signal corresponds to 1–4 atoms, respectively, initially loaded into the MOT and subsequently stored and detected in the cavity. In (e), storage of a single atom in the cavity for 15 s is shown.

Figure 4

In (a) an atom is swept across the cavity mode at a slow speed, $v=55\mu \mathrm{m}/\mathrm{s}$, to achieve the high resolution scan shown. These data are the average of 17 experimental runs which are fit to a Gaussian function. (b) and (c) show a single atom swept across the cavity mode 10 and 75 times with a speed of $440\mu \mathrm{m}/\mathrm{s}$ and $4.4\mathrm{mm}/\mathrm{s}$, respectively.

Figure 5

(a) Single atom scattering rate versus probe beam power. The solid line is a linear fit to the data as expected from the dependence of the scattering rate to the probe beam power. The first three points are dark counts and are not included in the fit. (b) The dependence of the single atom scattering rate with respect to the cavity detuning ${\Delta }_C$. The solid line is a fit to a Lorentzian function.