METHOD AND SYSTEM FOR OPERATING AN ATOMIC CLOCK WITH ALTERNATING-POLARIZATION LIGHT

摘要

The present invention provides a method and apparatus for increasing the intensity of coherent population trapping (CPT) resonances, used in atomic clocks and magnetometers, by pumping the atoms with light of alternating polarization. Pumping with such light, characterized by a photon spin vector that alternates in direction at a hyperfine frequency of the atoms at the location of the atoms, is referred to as push-pull pumping. In one embodiment of the system of the present invention, alkali-metal vapor is pumped with alternating circular-polarization D 1 laser light that is intensity modulated at appropriate resonance frequencies, thereby exciting CPT resonances, which can be observed as increase in the mean transmittanee of the alkali-metal vapor. These resonances are substantially enhanced due to an, optically-induced concentration of atoms in the resonant energy sublevels.