Abstract

The usual way of obtaining laser cooled atoms at high densities is to use a magneto-optical trap.¹ In such a spontaneous force trap, the optical Earnshaw theorem is circumvented^2,3 by use of a magnetic field gradient together with optical pumping. Unfortunately, in many experiments such as frequency standards or-sub-recoil cooling,^4,5 this magnetic field may cause severe limitations, owing to the difficulty of removing residual fields after the operation of the magneto-optical trap.

© 1994 IEEE