A magneto-optical trap with millimeter ball lenses

We present a magneto-optical trap (MOT) design based on millimeter ball lenses, contained within a metal cube of 0.75$^{\prime \prime}$ side length. We present evidence of trapping approximately $4.2\times 10^5$ of $^{85}$Rb atoms with a number density of $3.2\times 10^9$ atoms/cm$^{3}$ and a loading time of 1.3 s. Measurement and a kinetic laser-cooling model are used to characterize the atom trap design. The design provides several advantages over other types of MOTs: the laser power requirement is low, the small lens and cube sizes allow for miniaturization of MOT applications, and the lack of large-diameter optical beam pathways prevents external blackbody radiation from entering the trapping region.