Frequency Combs for Cooling and Trapping

Andrew and Xueping have successfully demonstrated a technique that is designed to laser cool and trap atoms such as hydrogen and carbon (see publications for a link to the paper).  These species play the starring role in organic chemistry, yet are essentially beyond the reach of laser cooling and trapping due to the extremely deep UV light needed for laser cooling them.  By using a frequency comb instead of a narrow-band laser, Xueping and Andrew have shown that a two-photon transition can be driven with far greater efficiency than a frequency doubled continuous wave laser can do, and that this comb can be used to cool and trap the atoms.  The trapping came as a surprise to us, because the possibility that spectator comb teeth drive an undesired transition seemed very likely to us.  Nonetheless, this technique works very well, and seems to open the door to ultracold physics and chemistry with these abundant species.