SISYPHUS POLARIZATION GRADIENT LASER COOLING OF CR ATOMS ON THE J=3, J'=2, 3 AND 4 TRANSITIONS

Sisyphus polarization gradient laser cooling has been performed in a o ne-dimensional lin perpendicular to lin laser beam configuration on ea ch of the three fine structure transitions 3d(5)4s(7)S(3)-3d(5)4p(7)P( 2,3,4) of Cr-52. Hence for the first time Sisyphus polarization gradie nt cooling on a J(e) = J(g) transition with J(g) > 1 has been demonstr ated. We have investigated the qualitative and quantitative difference s between the cooling process for three transitions with J(e) = J(g) - 1, J(g), J(g) + 1 (J(g) > 1). A major qualitative difference of the l aser cooling on the J(g) = 3 --> J(e) = 4 and J(g) = 3 --> J(e) = 2, 3 transitions has been observed as expected from simple theoretical arg uments. In the case of J(e) less than or equal to J(g) sub-Doppler coo ling is achieved when the laser detuning is blue. Even though the situ ation for the J(e) = 2 and J(e) = 3 case is qualitatively similar, we find quantitative differences which are in good agreement with Monte C arlo wavefunction simulations. For experiments where narrow velocity d istributions are essential, such as atom lithography, these results ca n be applied.