Abstracto

Sub-Doppler Cooling of 87Rb for Transportable Gravimeter

We have demonstrated the sub-Doppler cooling of ⁸⁷Rb in a 3D MOT as a first step toward realizing a cold-atom mobile gravimeter. A com-pact Ti-UHV chamber is designed for this purpose and has achieved sub-Doppler cooling of ⁸⁷Rb atoms to a temperature of ~16 µK through a multistage cooling sequence. Sub-Doppler laser cooling requires optical pumping among differently light-shifted ground-state sublevels. We describe the study and characterization of the sub-Doppler cooling in a real MOT with σ⁺ − σ⁻ beam configuration. A theoretical overview is provided, and the experimental setup is described in detail.