  Laser cooling to sub-Doppler temperatures by optical molasses is thought to
be inhibited in atoms with unresolved, near-degenerate hyperfine structure in
the excited state. We demonstrate that such cooling is possible in one to three
dimensions, not only near the standard D2 line for laser cooling, but over a
range extending to the D1 line. Via a combination of Sisyphus cooling followed
by adiabatic expansion, we reach temperatures as low as 40 \mu K, which
corresponds to atomic velocities a factor of 2.6 above the limit imposed by a
single photon recoil. Our method requires modest laser power at a frequency
within reach of standard frequency locking methods. It is largely insensitive
to laser power, polarization and detuning, magnetic fields, and initial
hyperfine populations. Our results suggest that optical molasses should be
possible with all alkali species.
