Laser cooling of gas atoms by “as Stark effect”

<正>Laser cooling and trapping of gas atoms is a new subject of great interest in laserspectroscopy. This paper makes a proposal for laser cooling of gas atoms via ac Starkeffect. The energy levels can induce atomic shift when the atom is irradiated by light.Experiments show that under the illumination of laser light the amounts of optical frequencyshifts are of the order of serveral GHz and the shift of the levels are quasi-transient innature. We take an atom with three level system as an example to illustrate this process.If an atom is irradiated by an intense laser pulse of frequency vl2 approximate to the