  We demonstrate direct laser cooling of a gas of rubidium 87 atoms to quantum
degeneracy. The method does not involve evaporative cooling, is fast, and
induces little atom loss. The atoms are trapped in a two-dimensional optical
lattice that enables cycles of cloud compression to increase the density,
followed by degenerate Raman sideband cooling to decrease the temperature.
Light-induced loss at high atomic density is substantially reduced by using far
red detuned optical pumping light. Starting with 2000 atoms, we prepare 1400
atoms in 300 ms at quantum degeneracy, as confirmed by the appearance of a
bimodal velocity distribution as the system crosses over from a classical gas
to a Bose-condensed, interacting one-dimensional gas with a macroscopic
population of the quantum ground state. The method should be broadly applicable
to many bosonic and fermionic species, and to systems where evaporative cooling
is not possible.
