Abstract

The magneto-optical trap (MOT) has become the workhorse in many laboratories around the world for studies of trapped atoms. To slow the atoms a high intensity is needed but is not required to trap atoms that have been cooled. Low light intensity at trap centre is desirable as collisions between ground-state and excited state atoms is a major route for trap loss. Thus, a cooling beam that has a high intensity away from trap centre but has a low intensity at trap centre would trap more atoms. By excluding the repumping light from the centre of a MOT a dramatic reduction in light-assisted loss is observed and a trap density of 10¹² cm^-3 may be achieved [1]. This technique is known as the dark magneto-optical trap.

© 1998 IEEE