Velocity Tuned Hyperfine Dark State Loading and Cooling in a dipole trap

We present a novel optical cooling scheme capable of loading and cooling atoms directly inside deep optical dipole traps utilizing hyperfine dark states. In the presence of strong light shifts of the upper excited states, this allows the velocity selective dark-state cooling of atoms into the conservative potential without loss of atoms. We report the lossless optical cooling inside the trap with a seven-fold increase in the number of atoms loaded. Our findings open the door to all-optical cooling of trapped atoms and molecules which lack the closed cycling transitions normally needed to achieve low temperatures and the high initial densities required for evaporative cooling.