PHASE-SHIFT INDUCED FROM THE DC STARK-EFFECT IN AN ATOM INTERFEROMETER COMPRISED OF 4 COPROPAGATING LASER-BEAMS

We observed the phase shift of the atomic wave function induced from t he dc Stark effect using an atom interferometer comprised of four copr opagating traveling laser beams. We calculated the interference signal for the interferometer in the case of a thermal atomic beam. By compa ring the observed interference fringes with the calculated ones, the d ifference between the polarizabilities of the P-3(1) state and the S-1 (0) state of calcium was obtained to be alpha(P-3(1)) - alpha(S-1(0)) = (13.4+/-2.0) X 10(-24) cm(3). This value was consistent with that de duced from the Stark frequency shift.