Sisyphus cooling of rubidium atoms on the D2(F=1→F'=1) line: the role of the neighbouring transitions

We study one-dimensional Sisyphus cooling on the 5S1/2(F=1)→5P3/2(F'=1) transition of 87Rb atoms in the electric field created by two counter-propagating linearly polarized laser beams with an angle of θ between the polarization directions. The neighbouring F'=0 and F'=2 excited states are found to play an important role in the cooling mechanism, e.g., by inhibiting a significant population of the velocity-selective dark state. Our experimental data, such as temperatures and probe absorption coefficients, agree well with the results of quantum Monte-Carlo wavefunction simulations. (orig.)