Abstract

We report on trapping of ⁴⁰K atoms at low temperatures and high densities in a far-detuned optical trap. The trap is a vertical standing-wave created with about 550 mW of radiation tuned 10 nm on the red of the D₂ transition, and is loaded from a sample held in a MOT at sub-Doppler temperatures [1], with the help of a temporal dark-spot phase and a magnetic compression phase. We are able to trap as many as 5×10⁶ atoms with a lifetime of 200 ms in the F=9/2 ground state. From the temperature of the trapped atoms, which is around 30 µK, and the measured trap frequencies (1 kHz radial, 500 kHz axial) we estimate a density of 5×10¹² cm^–3.

© 2000 IEEE