Polarization Enhanced Deep Optical Dipole Trapping of Λ-Cooled Polar Molecules

We demonstrate loading of SrF molecules into an optical dipole trap (ODT) via in-trap.-enhanced gray molasses cooling. We find that this cooling can be optimized by a proper choice of relative ODT and cooling beam polarizations. In this optimized configuration, we observe molecules with temperatures as low as 14(1) mu K in traps with depths up to 570 mu K. With optimized parameters, we transfer similar to 5% of molecules from our radio-frequency magneto-optical trap into the ODT, at a density of similar to 2 x 10(9) cm(-3), a phase space density of similar to 2 x 10(-7), and with a trap lifetime of similar to 1 s.

Automated summary

By optimizing cooling parameters and selecting appropriate beam polarizations, we successfully loaded SrF molecules into an optical dipole trap and observed the behavior of molecules at temperatures as low as 14 mu K.