Laser cooling in an optical lattice that employs Raman transitions

We demonstrate laser cooling in an optical lattice that employs Raman transitions. Four laser beams with different frequencies form a one-dimensional lattice with a basic lattice period that is a factor of 2 less than in standard optical lattices. Rb atoms are cooled to 8 mu K. We measure the intensity- and detuning-dependence of the cooling mechanism. Our experimental results agree well with theoretical models.