Laser cooling at high density in deep far-detuned optical lattices

We report a way to overcome heating due to the reabsorption of scattered li ght when relatively many atoms are laser cooled at high density. A sample o f 8 x 10(7) Cs atoms, with 6 x 10(11) atoms cm(-3), is loaded into a deep f ar-detuned one-dimensional optical lattice, which acts as a large volume th ree-dimensional (3D) trap. Polarization gradient cooling with a separate se t of cooling beams is found to work well in this trap, populating the; trap 's vibrational ground state with more than half the atoms. After cooling, t he lattice is shut off adiabatically, leaving a still dense sample at 1.2 m u K. We propose and demonstrate a generalization to a 3D lattice, which wil l allow many more atoms to be loaded into conservative light traps, and can greatly increase the initial phase-space density for loading magnetic trap s. [S1050-2947(99)51201-8].