ONE-DIMENSIONAL LASER COOLING WITH LINEARLY POLARIZED FIELDS

We present a calculation of one-dimensional sub-Doppler cooling of neutral atoms, in which the atomic center-of-mass motion is quantized. The cooling field consists of a pair of counterpropagating, linearly polarized laser beams, with their polarizaton vectors at an angle theta with respect to each other. The steady-state atomic density matrix is analyzed as a function of theta. It is shown that, depending on the internal atomic level scheme, the equilibrium population of the quantized ground state of atomic center-of-mass motion can either increase or decrease significantly when theta is reduced from pi/2. These effects are interpreted based on the spatial localization of atoms in the light-induced potential wells.