DOPPLER-FREE 2-COLOR SPECTROSCOPY OF THE 6(2)S(1 2)-8(2)S(1/2)CESIUM TRANSITION USING SEMICONDUCTOR DIODE-LASERS/

We report an experimental investigation of the 6S-8S transition of ces ium atoms by using Doppler-free two-color spectroscopy. We consider th e case in which one of the laser frequencies is nearly resonant with t he 6S(1/2)-6P(3/2) transition while a second one is swept around the 6 P(3/2)-8S(1/2) transition. The lineshapes of two-photon absorption spe ctra are analyzed taking into account the effects of saturation and co llisions. Both counterpropagating and copropagating laser-beam schemes are studied. Although for the linewidths are broader copropagating be ams, such a scheme has proved advantageous to fully resolve the hyperf ine structure of the final state 8S(1/2) and, hence, to measure the di pole magnetic constant A of this state.