  Some practical improvements are proposed for the "optical-shaker"
laser-cooling technique [I.S. Averbukh and Y. Prior, Phys. Rev. Lett. 94,
153002 (2005)]. The improved technique results in an increased cooling rate and
decreases the minimum cooling temperature achievable with the optical shaker.
The modified shaker requires only one measurement of the force on the atoms
before each cooling step, resulting in a simplification of the feedback
electronics. The force is inferred from the power variations of the transmitted
laser beams and is used to determine the best moment at which the cooling steps
are applied. The temperature of the atomic system is automatically monitored,
which allows maintaining an optimum cooling rate as the temperature decreases.
The improved shaker is simple to build, provides a faster rate of cooling, and
can work in the microkelvin regime. Numerical modeling shows a reduction by a
factor of three in the required number of phase jumps and a lower temperature
limit reduced by an order of magnitude compared to the initially proposed
shaker. The technique is also extendable to cooling in three dimensions.
