Abstract

The radiation force on a two-level atom in a standing wave has been well investigated.^[1] A moving atom in a standing wave losses or gets kinetic energy when the field intensity increases. In 1979, one of the authors proposed a cooling mechanism, which we called AC Stark radiation cooling.^[2] Consider a three-level system, the ground state and first excited state are connected by a CW laser and the first and second excited states are connected by a pulsed laser. Because of AC Stark effect, the first excited state would be shifted and modulated with the frequency same as the modulated frequency of pulsed laser. If the atom absorbs a photon from CW laser and transits from the ground state to the first excited state when the pulsed laser on and emits the photon spontaneously when the pulsed laser off. Thus there is a energy difference between absorbed and emitted photons. This difference should be compensated by the atomic kinetic energy and thus the atom can be cooled. The physical analysis shows that this system can be worked.

© 1992 IQEC