Fluorescence kinetics of particles decelerated in a laser field

An investigation is made of the time dependences of the fluorescence of single particles and of an ensemble of particles having a velocity distribution when their spectrum is scanned by decelerating them under the action of radiation pressure. A comparison is made with similar dependences obtained on uniformly sweeping the laser frequency without changing the particle velocity. Spectral scanning by the deceleration method is demonstrated experimentally for a beam of sodium atoms.