Demonstration of a Sagnac-Type Cold Atom Interferometer with Stimulated Raman Transitions

Cold-matter-wave Sagnac interferometers possess many advantages over their thermal atomic beam counterparts when they are used as precise inertial sensors. We report a realization of a Sagnac-type interferometer with cold atoms. Cold rubidium atoms are prepared in a magneto-optical trap and are pushed by resonant laser pulse to form slow atomic beam. In the interference region, atomic wave packets are coherently manipulated using π/2-π-π/2 Raman pulse sequences. Interference fringes with maximum contrast of 37% are observed experimentally.