OBSERVATION OF COLLIMATION AND DECOLLIMATION OF AN ATOMIC-BEAM IN A MISALIGNED STANDING-WAVE

This paper reports an experimental study on the collimation and decoll imation of an atomic beam in a misaligned standing wave, in which the effective detuning caused by the Doppler effect is affected by the lon gitudinal velocity of the atomic beam. The experiment shows that in a strong field with red detuning between laser field and atomic transiti on frequency, laser heating in a normal standing wave becomes laser co oling in a misaligned standing wave for an approriate misalignment ang le. For blue detuning, laser cooling in a standing wave can also becom e laser heating in a misaligned standing wave for an appropriate condi tion. These results ca be used in controling atomic motion.