Stimulated light forces using picosecond laser pulses

Using the stimulated force exerted by counterpropagating picosecond laser pulses from a mode-locked Ti:Sapphire laser we were able to focus a beam of laser-cooled cesium atoms along one dimension to about 57% of its original width in the detection zone. The force profile was measured outside and inside the overlap region of the pulses and found to be in agreement with an earlier theoretical prediction(1). A brief theoretical account of the interaction of atoms with pulsed laser light based on the optical Bloch equations is given.