Optimizing Bichromatic Force Decelerators for Atoms and Molecules

Optical bichromatic forces (BCFs) have shown success in slowing atomic beams,\footnote{M. A. Chieda and E. E. Eyler, PRA \textbf{86}, 053415 (2012), and references therein.} and they have considerable promise for laser slowing of molecules. Our first-generation BCF decelerator for metastable helium has achieved slowing by $>$500~m/s in less than 5~cm using ordinary diode lasers, with He* brightness similar to a Zeeman slower. We discuss explorations of atomic and molecular evolution under multicolor illumination with a view towards optimizing decelerators for MOT loading. These explorations include numerical studies of the excited-state fraction for two-level atoms in bichromatic and polychromatic light, progress towards a multi-level simulation for testing molecular behavior, and continuing investigations of the large-detuning limit of the BCF magnitude. We also discuss progress in developing a practical BCF decelerator for molecules, which could substantially improve on recent results using Doppler and Sisyphus forces.\footnote{J. F. Barry, \textit{et al.}, PRL \textbf{108}, 103002 (2012); M. Zeppenfeld, $et. al.$, Nature \textbf{491}, 570 (2012).} Our initial experimental configuration is a BCF-based beam deflector for CaF molecules.